Re: Directory creation
srinivasan srinivas wrote: Can someone tell me is there any module available to create directories?? I tried os, tempfile. I was facing some issues with os.mkdir(). The mode setting was not proper with this method. I created the directory 'stdin' with '0700' mode using os.mkdir() method. $> ls -alR stdin/ stdin/: total 12 drwx--S--- 2 munisams munisams 4096 Sep 3 02:00 . What is that 'S' in the group permission field?? David Wright explained why this is the expected behaviour last time you posted about this: http://groups.google.com/group/comp.lang.python/msg/f6a91447f1739e66 -- http://mail.python.org/mailman/listinfo/python-list
unexpected class behaviour
Hi all, can anyone explain the behaviour of the following code sniplet: ---> schnipp <--- class Base(object): def __init__( self, lst=[] ): self.varlist = lst def addVar( self, var ): self.varlist.append(var) class Derived(Base): def __init__( self, var ): Base.__init__(self) self.addVar(var) vars = ['foo', 'bar'] for ivar in vars: obj = Derived(ivar) print ivar, obj, obj.varlist ---> schnapp <--- After running (Python 2.5.1), I get the following output: foo <__main__.Derived object at 0xb7c608cc> ['foo'] bar <__main__.Derived object at 0xb7c6092c> ['foo', 'bar'] So, I get two different objects, but how does the 'foo' get into the second varlist? I'm a little bit confused about this, any ideas? Thanks in advance Jan -- http://mail.python.org/mailman/listinfo/python-list
tracking collection modification
I'm working on a remote object system, something kinda like Pyro. For the purposes of caching I need to be able to tell if a given dict / list / set has been modified. Ideally what I'd like is for them to have a modification count variable that increments every time the particular collection is modified. Unfortunately I can't find anything like that and since this needs to work for the regular normal list / dict / set objects subclassing them to add the modification count isn't useful. I realize I could take a copy and then compare the copy to the original, but that's a fairly heavy handed approach and I was hoping for something light and fast. Does anyone have any suggestions on best to approach this? -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected class behaviour
Jan Schäfer wrote: can anyone explain the behaviour of the following code sniplet: well, it *is* explained in the tutorial, the language reference, and the FAQ, so yes, it can be explained ;-) for more information, see this page: http://effbot.org/zone/default-values.htm -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected class behaviour
On 7 sep, 12:40, Fredrik Lundh <[EMAIL PROTECTED]> wrote: > Jan Schäfer wrote: > > can anyone explain the behaviour of the following code sniplet: > > well, it *is* explained in the tutorial, the language reference, and the > FAQ, so yes, it can be explained ;-) > > for more information, see this page: > > http://effbot.org/zone/default-values.htm > > Well, you may want replace the last line by: print ivar, obj, obj.varlist, id(obj.varlist) To have another behavior, you may want replace the 3 first lines by: class Base(object): def __init__( self, lst=None ): if lst is None: lst=[] self.varlist = lst Enjoy Python ! -- http://mail.python.org/mailman/listinfo/python-list
Re: List of modules available for import inside Python?
En Sat, 06 Sep 2008 17:18:55 -0300, clurker <[EMAIL PROTECTED]> escribió: > Michele Simionato wrote: > >> On Aug 28, 6:21 am, ssecorp <[EMAIL PROTECTED]> wrote: >>> Is there a way to view all the modules I have available for import >>> from within Python? >>> Like writing in the interpreter: >> >> Try: >> > help() >> help> modules >> Please wait a moment while I gather a list of all available modules... >> > > This looks like it could be a useful tool, but when I try it > I get the following: > > Please wait a moment while I gather a list of all available modules... [...] > File "/usr/local/lib/python2.5/site-packages/PIL/__init__.py", line 1342, > in > > File "/usr/local/lib/python2.5/site-packages/PIL/__init__.py", line 927, > in main > > UnboundLocalError: local variable 'given_files' referenced before assignment Unfortunately the "modules" help command actually imports all the available packages, and a buggy one may stop the whole process with an error. > Apparently python knows about them both, but I don't know I > haven't introduced an incompatibility somewhere...and that PIL > package showing up at the tail of the errors was one of my > more recent additions... If import of a package fails, the error reported is not accurate. In this case, probably some other package failed, that itself imported PIL. Line 927 in PIL/__init__.py does not exist. A quick fix is to replace line 1854 in pydoc.py (ModuleScanner.run) with this one: for importer, modname, ispkg in pkgutil.walk_packages(onerror=lambda name:None): (the onerror argument makes it to ignore all errors) -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: modules path
En Sat, 06 Sep 2008 20:26:24 -0300, Python <[EMAIL PROTECTED]> escribió: > now one question came up, how do I make those path permanent? > i mean, sys.path.append( adds it for the current session, > yet when i logout of IDLE and start it again it's gone... > how do i keep it in there? You can add that path to the PYTHONPATH environment variable, or you can put a .pth file in the current Lib directory, containing the desired path. See http://docs.python.org/inst/search-path.html and the documentation for the site module (although it appears not to be totally accurate). -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Error importing mxTidy
I built and installed mx-experimental 3.0.0 from source and it seemed to go fine. But when I try to import it, I get this: localhost% python -c "import mx.Tidy" Traceback (most recent call last): File "", line 1, in ? File "mx/Tidy/__init__.py", line 7, in ? from Tidy import * File "mx/Tidy/Tidy.py", line 7, in ? from mxTidy import * File "mx/Tidy/mxTidy/__init__.py", line 7, in ? from mxTidy import * ImportError: No module named mxTidy This seems strange to me, since it found the mx.Tidy module but not the mxTidy module underneath it. But I guess I don't know how the mx-experimental classes are put together, so I can't really guess what is happening. Thus I am posting here. :) -- [EMAIL PROTECTED] SDF Public Access UNIX System - http://sdf.lonestar.org -- http://mail.python.org/mailman/listinfo/python-list
Python and M2Crypto question
Hi all! I am trying to install M2Crypto to work on OSX10.5 apache (mod_python). Error I receive: Error was: dlopen(/Library/WebServer/eggs/M2Crypto-0.18.2-py2.5- macosx-10.5-i386.egg-tmp/M2Crypto/__m2crypto.so, 2): no suitable image found. Did find: /Library/WebServer/eggs/M2Crypto-0.18.2-py2.5-macosx-10.5-i386.egg- tmp/M2Crypto/__m2crypto.so: no matching architecture in universal wrapper I guess that have to do something with x64 architecture but I am stucked and not able to find a way and to make this work. M2Crypto lib works good stand alone. Any help appreciated, Bojan -- http://mail.python.org/mailman/listinfo/python-list
doctest not seeing any of my doc tests
I have a function in my module: def selftest(verbose=False): import doctest doctest.testmod(verbose=verbose) When I run it, it fails to find any of my doc tests, including the tests in __main__, and in fact it looks like it can't even find my functions and classes: >>> mymodule.selftest(True) 1 items had no tests: __main__ 0 tests in 1 items. 0 passed and 0 failed. Test passed. The second and subsequent times I call selftest, I get the same result except that it adds this line to the end: *** DocTestRunner.merge: '__main__' in both testers; summing outcomes. I've exited from Python and restarted the interactive interpreter. I've deleted the module .pyc file. Neither has helped. I've tried reading over the doctest module to see if there are any hints as to what's going wrong, but it's quite opaque to me. If there's anyone out there with a good understanding of doctest, I'd appreciate some pointers for where to start looking, or otherwise how to fix this problem. For what it's worth, I'm running Python 2.5 (r25:51908, Apr 10 2007, 10:29:13) [GCC 4.1.2 20070403 (Red Hat 4.1.2-8)] on linux2 -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: doctest not seeing any of my doc tests
Steven D'Aprano wrote: I have a function in my module: def selftest(verbose=False): import doctest doctest.testmod(verbose=verbose) what happens if you change the above to def selftest(verbose=False): import doctest, yourmodule doctest.testmod(yourmodule, verbose=verbose) (where yourmodule is the name of your module, obviously) -- http://mail.python.org/mailman/listinfo/python-list
[ANN] The Python Papers Vol 3 Iss 2 in one PDF
Hi everyone Our original release of TPP Volume 3 Issue 2 is in the form of one PDF per article. A number of readers had kindly requested for a parallel release for the entire issue in a single PDF for easy transport. Despite prevalent "industrial standards" for one PDF per article such as IEEE and ACM, we can understand our readers' point of view. We can see mutually exclusive advantages of both system - one PDF per article allows for tracking of view counts for each article whereas one PDF per issue allows for easy transport and offline browsing. Therefore, we had chose to released the entire volume as a single PDF in parallel and will continue to do so in future. The entire Volume 2 Issue 3 can be accessed from http://www.pythonpapers.org. We look forward to your continued support and contributions. Regards Maurice Ling Co-EIC, TPPA -- http://mail.python.org/mailman/listinfo/python-list
Re: doctest not seeing any of my doc tests
Steven D'Aprano, first of all you can try to run a minimal module, to see if your doctesting works, like: """ >>> 1 + 1 3 """ def foo(): """ >>> foo() 1 """ return 0 import doctest doctest.testmod() If that works correctly, then you can show us some more of the code and tests. Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list
Re: Not fully understanding the role of Queue.task_done()
In article <[EMAIL PROTECTED]>, Fredrik Lundh <[EMAIL PROTECTED]> wrote: >Martin DeMello wrote: >> >> In the interests of not hammering the db unnecessarily, I'm >> considering the following >> 1. A series of independent "monitor" threads that collect information >> over TCP from the cluster of machines, and write it to a queue >> 2. A "logger" thread that empties the queue every second or so and >> inserts the collected information to the db via a single insert >> statement > >why are you using a queue for this case, btw? why not just use a plain list > > L = [] > lock = threading.Lock() > >and add stuff using append in the monitor threads > > with lock: > L.append(item) Because using a queue requires less thinking. I certainly would use a queue in this case instead of rolling my own. -- Aahz ([EMAIL PROTECTED]) <*> http://www.pythoncraft.com/ "Argue for your limitations, and sure enough they're yours." --Richard Bach -- http://mail.python.org/mailman/listinfo/python-list
Re: Not fully understanding the role of Queue.task_done()
Aahz wrote: why are you using a queue for this case, btw? why not just use a plain list L = [] lock = threading.Lock() and add stuff using append in the monitor threads with lock: L.append(item) Because using a queue requires less thinking. given that the whole reason for this thread was that Queue API didn't fit the OP:s problem, that's a rather dubious statement. (btw, I've always thought that Python was all about making it easy to express the solution to a given problem in code, not to let you write programs without using your brain. when did that change?) -- http://mail.python.org/mailman/listinfo/python-list
Re: atomic section in code
Hendrik van Rooyen schrieb: Fredrik Lundh wrote: sounds like he wants/needs non-cooperative, mandatory locking. Could one get there using ctypes to disable interrupts? Not as such, ctypes can't execute arbitrary machine code. But of course you can create a C-lib that does what you want (IF it can be done, that is..), and wrap that. Cross Platform? Certainly not. I can think of lots of hassles, starting with permissions to use the privileged instructions. I don't think there is a chance for this without major system tinkering. Under Linux, you could create a real time thread so highly prioritized that it won't yield any time to any other scheduler. And in a kernel-module, you can call cli (or whatever the needed call is). But this will most probably break your system. diez -- http://mail.python.org/mailman/listinfo/python-list
firefox timestamp
hi all, -- http://mail.python.org/mailman/listinfo/python-list
Re: modules path
On 7 sep 2008, at 13:50, Gabriel Genellina wrote: En Sat, 06 Sep 2008 20:26:24 -0300, Python <[EMAIL PROTECTED]> escribió: now one question came up, how do I make those path permanent? i mean, sys.path.append( adds it for the current session, yet when i logout of IDLE and start it again it's gone... how do i keep it in there? You can add that path to the PYTHONPATH environment variable, or you can put a .pth file in the current Lib directory, containing the desired path. See http://docs.python.org/inst/search-path.html and the documentation for the site module (although it appears not to be totally accurate). -- Gabriel Genellina i read that but was wondering why some modules installed by macports did show up in the path and some didn't the PYTHONPATH wasn't set anywhere in my shell I did add it and now it works! Thanks John & Gabriel! gr Arno -- http://mail.python.org/mailman/listinfo/python-list
Re: [ANN] pysqlite 2.5.0 released
Hi,
- - Connection.enable_load_extension(enabled) to allow/disallow extension
loading. Allows you to use fulltext search extension, for example ;-)
The following code (from the docs) produces an error:
from pysqlite2 import dbapi2 as sqlite3
con = sqlite3.connect(":memory:")
# Load the fulltext search extension
con.enable_load_extension(True)
con.execute("select load_extension('./fts3.so')")
con.enable_load_extension(False)
Error is:
con.execute("select load_extension('./fts3.so')")
pysqlite2._sqlite.OperationalError: Das angegebene Modul wurde nicht gefunden.
Where should I look for the module?
Matthias
--
http://mail.python.org/mailman/listinfo/python-list
formatting a string with thousands separators
anyone recommend a way of formatting floats with comma separators? e.g. 50.00 -> 500,000.00 -- http://mail.python.org/mailman/listinfo/python-list
__builtins__ magic behavior
__builtins__ in 2.5.2 doesn't seem to behave like I remember it did
the last time I did some custom stuff with it, a very long time ago.
This isn't surprising, because of ongoing optimization, but it's hard
to google for '__builtins__' so I didn't really find any documentation
on the current CPython behavior, which in some cases seems quite
strange to me.
The documentation node at http://docs.python.org/ref/naming.html has a
"here be dragons" note on __builtins__, which is nice as far as it
goes, but doesn't provide any help for people wanting to abuse the
current CPython implementation. Additionally, the sentence
immediately above the note, "__builtins__ can be set to a user-created
dictionary to create a weak form of restricted execution" not only
contradicts the note, but in some cases appears not to be true.
When the code below is run, either standalone or by importing it, the
builtins used are different depending on whether exec is used with
globals() or with a copy of globals(). Any explanations for this
behavior would be much appreciated.
Thanks,
Pat
Executing:
{{{
original = __builtins__
if hasattr(original, '__dict__'): original = original.__dict__
copy = original.copy()
# Make the dictionaries different and use new one
copy['foo'] = 'bar'
del copy['len']
del original['chr']
__builtins__ = copy
testcode = '''
try: print foo
except: print "foo not found"
try: print len
except: print "len not found"
try: print chr
except: print "chr not found"
print
'''
x = globals()
assert type(x) is dict
y = {}
y.update(x)
assert y == x
print 'Executing in globals()'
exec testcode in x
print 'Executing in copy'
exec testcode in y
}}}
results in:
Executing in globals()
foo not found
chr not found
Executing in copy
bar
len not found
--
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Re: max(), sum(), next()
On Sep 6, 11:05�pm, Steven D'Aprano <[EMAIL PROTECTED] cybersource.com.au> wrote: > On Sat, 06 Sep 2008 11:22:07 -0700, Mensanator wrote: > > [...] > > >> They could have decided that sum must take at least two arguments, > >> because addition requires two arguments and it's meaningless to talk > >> about adding a single number without talking about adding it to > >> something else. But they didn't. > > > Ok. But the problem is they DID in SQL: x + Null = Null. > > Sheesh. That's not a problem, because Python is not trying to be a > dialect of SQL. And yet, they added a Sqlite3 module. > > If you want a NULL object, then there are recipes on the web that will > give you one. Then all you need to do is call sum(alist or [NULL]) and it > will give you the behaviour you want. Actualy, I already get the behaviour I want. sum([1,None]) throws an exception. I don't see why sum([]) doesn't throw an exception also (I understand that behaviour is by design, I'm merely pointing out that the design doesn't cover every situation). > > [...] > > > Here's a real world example (no ivory tower stuff): > > > An oil refinery client has just excavated a big pile of dirt to lay a > > new pipeline. > [snip details] > > Can't I just use a sum of 0 to tell me when data is missing? No, because > > in some cases the reporting limit of undetected compounds is set to 0. > > You can't use a sum of 0 to indicate when data is missing, full stop. Exactly. That's why I would prefer sum([]) to raise an exception instead of giving a false positive. > The > data may require 15 tests when only 3 have actually been done: > > sum([1.2e-7, 9.34e-6, 2.06e-8]) Biggest problem here is that it is often unknown just how many records you're supposed to get from the query, so we can't tell that a count of 3 is supposed to be 15. > > Missing data and a non-zero sum. How should sum() deal with that? That's a seperate issue and I'm not saying it should as long as the list contains actual numbers to sum. sum([1.2e-7, 9.34e-6, 2.06e-8, None]) will raise an exception, as it should. But what types are contained in []? > > The answer is that sum() can't deal with that. You can't expect sum() to > read your mind, know that there should be 15 items instead of 3, and > raise an error. So why do you expect sum() to read your mind and > magically know that zero items is an error, especially when for many > applications it is NOT an error? For the simple reason it doesn't have to read your mind, a mechanism has already been built into the function: start value. For those situations where an empty list is desired to sum to 0, you could use sum(alist,0) and use sum(alist) for those cases where summing an empty list is meaningless. Shouldn't you have to explicitly tell sum() how deal with situations like empty lists rather than have it implicitly assume a starting value of 0 when you didn't ask for it? > > The behaviour you want for this specific application is unwanted, > unnecessary and even undesirable for many other applications. The > solution is for *you* to write application-specific code to do what your > application needs, instead of relying on a general purpose function > magically knowing what you want. Does division magically know what you want? No, it raises an exception when you do something like divide by 0. Isn't it Pythonic to not write a litany of tests to cover every possible case, but instead use try:except? But try:except only works if the errors are recognized. And sum() says that summing an empty list is NEVER an error under ANY circumstance. That may be true in MOST cases, but it certainly isn't true in ALL cases. > > -- > Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Sep 7, 12:30 pm, Mensanator <[EMAIL PROTECTED]> wrote: > On Sep 6, 11:05 pm, Steven D'Aprano <[EMAIL PROTECTED] > > Sheesh. That's not a problem, because Python is not trying to be a > > dialect of SQL. > > And yet, they added a Sqlite3 module. Does that mean that, because there is an 'os' module, Python is trying to compete with Linux and Windows? This is starting to feel like a troll, but JUST IN CASE you are really serious about wanting to get work done with Python, rather than complaining about how it is not perfect, I offer the following snippet which will show you how you can test the results of a sum() to see if there were any items in the list: >>> class MyZero(int): ... pass ... >>> zero = MyZero() >>> x=sum([], zero) >>> isinstance(x,MyZero) True >>> x = sum([1,2,3], zero) >>> isinstance(x,MyZero) False >>> -- http://mail.python.org/mailman/listinfo/python-list
Re: formatting a string with thousands separators
On 9/7/2008 12:22 PM SimonPalmer apparently wrote: anyone recommend a way of formatting floats with comma separators? http://code.activestate.com/recipes/498181/ Alan Isaac -- http://mail.python.org/mailman/listinfo/python-list
Re: __builtins__ magic behavior
En Sun, 07 Sep 2008 14:00:48 -0300, Patrick Maupin <[EMAIL PROTECTED]> escribió: > __builtins__ in 2.5.2 doesn't seem to behave like I remember it did > the last time I did some custom stuff with it, a very long time ago. > > This isn't surprising, because of ongoing optimization, but it's hard > to google for '__builtins__' so I didn't really find any documentation > on the current CPython behavior, which in some cases seems quite > strange to me. > > The documentation node at http://docs.python.org/ref/naming.html has a > "here be dragons" note on __builtins__, which is nice as far as it > goes, but doesn't provide any help for people wanting to abuse the > current CPython implementation. Additionally, the sentence > immediately above the note, "__builtins__ can be set to a user-created > dictionary to create a weak form of restricted execution" not only > contradicts the note, but in some cases appears not to be true. > > When the code below is run, either standalone or by importing it, the > builtins used are different depending on whether exec is used with > globals() or with a copy of globals(). Any explanations for this > behavior would be much appreciated. Python takes some shortcuts when dealing with builtins. I'll just describe what happens (I won't say whether it is "right" or "wrong"). The exec statement, when given a string source, compiles it and eventually calls PyEval_EvalCodeEx, which creates a new frame using PyFrame_New and finally executes it. A frame object contains a pointer to the previous frame, the code to be executed, a pointer to the current globals *and* a separate pointer to the current builtins. Inside PyFrame_New, there is a shortcut: if the new frame and the previous one share the same globals, then the previous builtins are copied into the new frame. Only if the globals differ the builtins are searched in globals. From frameobject.c: /* If we share the globals, we share the builtins. Save a lookup and a call. */ It is this assumption that fails in your code. If you want to execute some code with modified builtins, do not change __builtins__ in the *calling* code, but in the globals that you pass to the exec call. That appears to be the most logical approach, and the way the developers appear to have expected. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
En Sun, 07 Sep 2008 14:30:09 -0300, Mensanator <[EMAIL PROTECTED]> escribió: > Actualy, I already get the behaviour I want. sum([1,None]) > throws an exception. I don't see why sum([]) doesn't throw > an exception also (I understand that behaviour is by design, > I'm merely pointing out that the design doesn't cover every > situation). [...] > Exactly. That's why I would prefer sum([]) to raise an > exception instead of giving a false positive. The built in behavior can't be good for every usage. Nobody prevents you from defining yoru own function tailored to your own specs, like this: def strict_sum(items): items = iter(items) try: first = items.next() except StopIteration: raise ValueError, "strict_sum with empty argument" return sum(items, first) Tweak as needed. Based on other posts I believe your Python skills are enough to write it on your own, so I don't see why you're complaining so hard about the current behavior. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: __builtins__ magic behavior
On Sep 7, 2:50 pm, "Gabriel Genellina" <[EMAIL PROTECTED]> wrote: > Inside PyFrame_New, there is a shortcut: if the new frame and > the previous one share the same globals, then the previous > builtins are copied into the new frame. Only if the globals > differ the builtins are searched in globals. From frameobject.c: > /* If we share the globals, we share the builtins. Save a > lookup and a call. */ That was exactly my problem. Thank you for the cogent explanation. > If you want to execute some code with modified builtins, do not > change __builtins__ in the *calling* code, but in the globals that > you pass to the exec call. That appears to be the most logical > approach, and the way the developers appear to have expected. Actually, my use-case is a tiny bit different than this. I am dynamically creating module objects, and was going nuts trying to comprehend the inner workings of behind-the-scenes __builtins__ magic in the module object, not realizing that the magic was actually in the execution frames. Thanks, Pat -- http://mail.python.org/mailman/listinfo/python-list
problem with permutations
I am trying to translate this elegant Erlang-code for finding all the permutations of a list. I think it is the same function as is but it doesn't work in Python. -- is upd in Python. It works as it should. perms([]) -> [[]]; perms(L) -> [[H|T] || H <- L, T <- perms(L--[H])]. def perms(lista): if lista == []: return [[]] else: for h in lista: return [([h]+[t]) for t in perms(upd(lista, h))] def upd(lista, elem, acc=tuple([])): lista = tuple(lista) if lista == (): return list(acc) if lista[0] == elem: return list(acc + tuple(lista[1:])) else: return upd(lista[1:], elem, acc + tuple([lista[0]])) -- http://mail.python.org/mailman/listinfo/python-list
Re: List of modules available for import inside Python?
Gabriel Genellina wrote: > En Sat, 06 Sep 2008 17:18:55 -0300, clurker <[EMAIL PROTECTED]> > escribió: > >> Michele Simionato wrote: >> >>> On Aug 28, 6:21 am, ssecorp <[EMAIL PROTECTED]> wrote: Is there a way to view all the modules I have available for import from within Python? Like writing in the interpreter: >>> >>> Try: >>> >> help() >>> help> modules >>> Please wait a moment while I gather a list of all available modules... >>> >> >> This looks like it could be a useful tool, but when I try it >> I get the following: >> >> Please wait a moment while I gather a list of all available modules... > [...] >> File "/usr/local/lib/python2.5/site-packages/PIL/__init__.py", line >> 1342, >> in >> >> File "/usr/local/lib/python2.5/site-packages/PIL/__init__.py", line >> 927, >> in main >> >> UnboundLocalError: local variable 'given_files' referenced before >> assignment > > > Unfortunately the "modules" help command actually imports all the > available packages, and a buggy one may stop the whole process with an > error. > >> Apparently python knows about them both, but I don't know I >> haven't introduced an incompatibility somewhere...and that PIL >> package showing up at the tail of the errors was one of my >> more recent additions... > > If import of a package fails, the error reported is not accurate. In this > case, probably some other package failed, that itself imported PIL. Line > 927 in PIL/__init__.py does not exist. > > A quick fix is to replace line 1854 in pydoc.py (ModuleScanner.run) with > this one: > > for importer, modname, ispkg in > pkgutil.walk_packages(onerror=lambda name:None): > > (the onerror argument makes it to ignore all errors) > nice Gabriel, thanx! At least now "help(); modules" gives me a beautiful list -- I guess I'll find out what the buggy module is if/when I try to use it...(all PIL/__init__.py is is about 15 lines of comments (referencing a README I can't find)) sc -- http://mail.python.org/mailman/listinfo/python-list
lacking follow-through
I am concerned by the lack of follow-through on some responses to recent ideas I have described. Do I merely have a wrong understanding of group policy? Is it a good policy (defined with respect to the future of Python and the welfare of humans at large) if so? Is there a serious lack of diligence, or should I merely take more initiative, and ignore charges of 'pestering'? (Warning, moderately deep outside social issues on table too.) -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
Hi, This is the strangest post I've seen since I've joined this list (only recently). What the ? cheers James On Mon, Sep 8, 2008 at 7:00 AM, castironpi <[EMAIL PROTECTED]> wrote: > I am concerned by the lack of follow-through on some responses to > recent ideas I have described. Do I merely have a wrong understanding > of group policy? Is it a good policy (defined with respect to the > future of Python and the welfare of humans at large) if so? Is there > a serious lack of diligence, or should I merely take more initiative, > and ignore charges of 'pestering'? (Warning, moderately deep outside > social issues on table too.) > -- > http://mail.python.org/mailman/listinfo/python-list > -- -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
Can we stop this thread now? :) I think we've all seen what the intended behavior of sum(), max() and other similar functions. cheers James On Mon, Sep 8, 2008 at 3:30 AM, Mensanator <[EMAIL PROTECTED]> wrote: > On Sep 6, 11:05�pm, Steven D'Aprano <[EMAIL PROTECTED] > cybersource.com.au> wrote: >> On Sat, 06 Sep 2008 11:22:07 -0700, Mensanator wrote: >> >> [...] >> >> >> They could have decided that sum must take at least two arguments, >> >> because addition requires two arguments and it's meaningless to talk >> >> about adding a single number without talking about adding it to >> >> something else. But they didn't. >> >> > Ok. But the problem is they DID in SQL: x + Null = Null. >> >> Sheesh. That's not a problem, because Python is not trying to be a >> dialect of SQL. > > And yet, they added a Sqlite3 module. > >> >> If you want a NULL object, then there are recipes on the web that will >> give you one. Then all you need to do is call sum(alist or [NULL]) and it >> will give you the behaviour you want. > > Actualy, I already get the behaviour I want. sum([1,None]) > throws an exception. I don't see why sum([]) doesn't throw > an exception also (I understand that behaviour is by design, > I'm merely pointing out that the design doesn't cover every > situation). > >> >> [...] >> >> > Here's a real world example (no ivory tower stuff): >> >> > An oil refinery client has just excavated a big pile of dirt to lay a >> > new pipeline. >> [snip details] >> > Can't I just use a sum of 0 to tell me when data is missing? No, because >> > in some cases the reporting limit of undetected compounds is set to 0. >> >> You can't use a sum of 0 to indicate when data is missing, full stop. > > Exactly. That's why I would prefer sum([]) to raise an > exception instead of giving a false positive. > >> The >> data may require 15 tests when only 3 have actually been done: >> >> sum([1.2e-7, 9.34e-6, 2.06e-8]) > > Biggest problem here is that it is often unknown just > how many records you're supposed to get from the query, > so we can't tell that a count of 3 is supposed to be 15. > >> >> Missing data and a non-zero sum. How should sum() deal with that? > > That's a seperate issue and I'm not saying it should as > long as the list contains actual numbers to sum. > sum([1.2e-7, 9.34e-6, 2.06e-8, None]) will raise an > exception, as it should. But what types are contained > in []? > >> >> The answer is that sum() can't deal with that. You can't expect sum() to >> read your mind, know that there should be 15 items instead of 3, and >> raise an error. So why do you expect sum() to read your mind and >> magically know that zero items is an error, especially when for many >> applications it is NOT an error? > > For the simple reason it doesn't have to read your mind, > a mechanism has already been built into the function: start > value. For those situations where an empty list is desired > to sum to 0, you could use sum(alist,0) and use sum(alist) for > those cases where summing an empty list is meaningless. > Shouldn't you have to explicitly tell sum() how deal with > situations like empty lists rather than have it implicitly > assume a starting value of 0 when you didn't ask for it? > >> >> The behaviour you want for this specific application is unwanted, >> unnecessary and even undesirable for many other applications. The >> solution is for *you* to write application-specific code to do what your >> application needs, instead of relying on a general purpose function >> magically knowing what you want. > > Does division magically know what you want? No, it raises an > exception when you do something like divide by 0. Isn't it > Pythonic to not write a litany of tests to cover every > possible case, but instead use try:except? > > But try:except only works if the errors are recognized. > And sum() says that summing an empty list is NEVER an error > under ANY circumstance. That may be true in MOST cases, but > it certainly isn't true in ALL cases. > >> >> -- >> Steven > > -- > http://mail.python.org/mailman/listinfo/python-list -- -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: problem with permutations
Hi, Here's a (better?) function: def permutate(seq): if not seq: return [seq] else: temp = [] for k in range(len(seq)): part = seq[:k] + seq[k+1:] for m in permutate(part): temp.append(seq[k:k+1] + m) return temp cheers James On Mon, Sep 8, 2008 at 6:47 AM, cnb <[EMAIL PROTECTED]> wrote: > I am trying to translate this elegant Erlang-code for finding all the > permutations of a list. > I think it is the same function as is but it doesn't work in Python. > -- is upd in Python. It works as it should. > > perms([]) -> [[]]; > perms(L) -> [[H|T] || H <- L, T <- perms(L--[H])]. > > def perms(lista): >if lista == []: >return [[]] >else: >for h in lista: >return [([h]+[t]) for t in perms(upd(lista, h))] > > def upd(lista, elem, acc=tuple([])): >lista = tuple(lista) >if lista == (): >return list(acc) >if lista[0] == elem: >return list(acc + tuple(lista[1:])) >else: >return upd(lista[1:], elem, acc + tuple([lista[0]])) > -- > http://mail.python.org/mailman/listinfo/python-list > -- -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: formatting a string with thousands separators
Hi,
There is a much easier more consistent way:
>>> import locale
>>> locale.setlocale(locale.LC_ALL, "en_AU.UTF-8")
'en_AU.UTF-8'
>>> locale.format("%0.2f", 500, True)
'5,000,000.00'
>>>
cheers
James
On Mon, Sep 8, 2008 at 5:24 AM, Alan G Isaac <[EMAIL PROTECTED]> wrote:
> On 9/7/2008 12:22 PM SimonPalmer apparently wrote:
>>
>> anyone recommend a way of formatting floats with comma separators?
>
>
> http://code.activestate.com/recipes/498181/
>
> Alan Isaac
> --
> http://mail.python.org/mailman/listinfo/python-list
>
--
--
-- "Problems are solved by method"
--
http://mail.python.org/mailman/listinfo/python-list
Updating python dictionary
Hello...
I have a dict of key/values and I want to change the keys in it, based
on another mapping dictionary. An example follows:
MAPPING_DICT = {
'a': 'A',
'b': 'B',
}
my_dict = {
'a': '1',
'b': '2'
}
I want the finished my_dict to look like:
my_dict = {
'A': '1',
'B': '2'
}
Whereby the keys in the original my_dict have been swapped out for the
keys mapped in MAPPING_DICT.
Is there a clever way to do this, or should I loop through both,
essentially creating a brand new dict?
Cheers,
Andy.
--
http://mail.python.org/mailman/listinfo/python-list
Re: formatting a string with thousands separators
James Mills wrote:
There is a much easier more consistent way:
import locale
locale.setlocale(locale.LC_ALL, "en_AU.UTF-8")
'en_AU.UTF-8'
doesn't work on all Python platforms, though:
>>> locale.setlocale(locale.LC_ALL, "en_AU.UTF-8")
Traceback (most recent call last):
File "", line 1, in
File "c:\python25\lib\locale.py", line 478, in setlocale
return _setlocale(category, locale)
locale.Error: unsupported locale setting
and is likely to give you somewhat unpredictable output if you use the
machine's actual locale:
>>> import os
>>> locale.setlocale(locale.LC_ALL, os.environ["LANG"])
'sv_SE.UTF-8'
>>> locale.format("%0.2f", 500, True)
'500,00'
--
http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
En Sun, 07 Sep 2008 18:00:30 -0300, castironpi <[EMAIL PROTECTED]> escribió: > I am concerned by the lack of follow-through on some responses to > recent ideas I have described. Do I merely have a wrong understanding > of group policy? Is it a good policy (defined with respect to the > future of Python and the welfare of humans at large) if so? Is there > a serious lack of diligence, or should I merely take more initiative, > and ignore charges of 'pestering'? (Warning, moderately deep outside > social issues on table too.) Maybe people just doesn't have anything to say? Last thing I remember from you, is some mmap-based tree, and I'm not interested. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Sun, 07 Sep 2008 14:51:32 -0700, [EMAIL PROTECTED] wrote:
> MAPPING_DICT = {
> 'a': 'A',
> 'b': 'B',
> }
>
> my_dict = {
> 'a': '1',
> 'b': '2'
> }
>
> I want the finished my_dict to look like:
>
> my_dict = {
> 'A': '1',
> 'B': '2'
> }
>
> Whereby the keys in the original my_dict have been swapped out for the
> keys mapped in MAPPING_DICT.
>
> Is there a clever way to do this, or should I loop through both,
> essentially creating a brand new dict?
You only have to loop through `my_dict`:
In [187]: %cpaste
Pasting code; enter '--' alone on the line to stop.
:MAPPING_DICT = {
:'a': 'A',
:'b': 'B',
:}
:
:my_dict = {
:'a': '1',
:'b': '2'
:}
:--
In [188]: dict((MAPPING_DICT[k], v) for k, v in my_dict.iteritems())
Out[188]: {'A': '1', 'B': '2'}
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Mon, 08 Sep 2008 07:34:55 +1000, James Mills wrote: > This is the strangest post I've seen > since I've joined this list (only > recently). What the ? Yeah, castironpi sometimes doesn't make much sense. Maybe because it's a bot!? :-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Sep 7, 2:51 pm, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote:
> Hello...
>
> I have a dict of key/values and I want to change the keys in it, based
> on another mapping dictionary. An example follows:
>
> MAPPING_DICT = {
> 'a': 'A',
> 'b': 'B',
>
> }
>
> my_dict = {
> 'a': '1',
> 'b': '2'
>
> }
>
> I want the finished my_dict to look like:
>
> my_dict = {
> 'A': '1',
> 'B': '2'
>
> }
>
> Whereby the keys in the original my_dict have been swapped out for the
> keys mapped in MAPPING_DICT.
>
> Is there a clever way to do this, or should I loop through both,
> essentially creating a brand new dict?
>
> Cheers,
> Andy.
You could accomplish this with something similar to the following:
new_dict = {}
for x in MAPPING_DICT.keys():
if x in my_dict.keys():
new_dict[MAPPING_DICT[x]] = my_dict[x]
Although there is probably a better solution to the problem your
having. Perhaps more details could help us lead in you the right
direction?
Cheers, MK
--
http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
[EMAIL PROTECTED] wrote: Is there a clever way to do this, or should I loop through both, essentially creating a brand new dict? since none of your dictionaries contain the keys you want in the final dictionary, creating a brand new dict sounds pretty clever to me. -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
Hi,
There is "never" a "clever" way
of doing anything, but:
$ cat test.py
MAPPING_DICT = {'a': 'A','b': 'B',}
my_dict = {'a': '1','b': '2'}
my_dict = dict((MAPPING_DICT[k], my_dict[k]) for k in my_dict)
print my_dict
$ python test.py
{'A': '1', 'B': '2'}
$
That should do the trick.
cheers
James
On Mon, Sep 8, 2008 at 7:51 AM, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> Hello...
>
> I have a dict of key/values and I want to change the keys in it, based
> on another mapping dictionary. An example follows:
>
> MAPPING_DICT = {
>'a': 'A',
>'b': 'B',
> }
>
> my_dict = {
>'a': '1',
>'b': '2'
> }
>
> I want the finished my_dict to look like:
>
> my_dict = {
>'A': '1',
>'B': '2'
> }
>
> Whereby the keys in the original my_dict have been swapped out for the
> keys mapped in MAPPING_DICT.
>
> Is there a clever way to do this, or should I loop through both,
> essentially creating a brand new dict?
>
> Cheers,
> Andy.
> --
> http://mail.python.org/mailman/listinfo/python-list
>
--
--
-- "Problems are solved by method"
--
http://mail.python.org/mailman/listinfo/python-list
Re: problem with permutations
cnb <[EMAIL PROTECTED]> writes: > perms([]) -> [[]]; > perms(L) -> [[H|T] || H <- L, T <- perms(L--[H])]. I think the most direct transcription might be: def perms(xs): if len(xs)==0: return [[]] return [([h]+t) for h in xs for t in perms([y for y in xs if y not in [h]])] But it is rather inefficient, as is the Erlang version. -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
En Sun, 07 Sep 2008 18:51:32 -0300, [EMAIL PROTECTED] <[EMAIL PROTECTED]>
escribió:
> I have a dict of key/values and I want to change the keys in it, based
> on another mapping dictionary. An example follows:
>
> MAPPING_DICT = {
> 'a': 'A',
> 'b': 'B',
> }
>
> my_dict = {
> 'a': '1',
> 'b': '2'
> }
>
> I want the finished my_dict to look like:
>
> my_dict = {
> 'A': '1',
> 'B': '2'
> }
>
> Whereby the keys in the original my_dict have been swapped out for the
> keys mapped in MAPPING_DICT.
>
> Is there a clever way to do this, or should I loop through both,
> essentially creating a brand new dict?
Exactly. You can do that in one pass:
my_new_dict = dict((MAPPING_DICT[k],v) for (k,v) in my_dict.iteritems())
That's enough if MAPPING_DICT always contains all the keys. If you want to keep
old keys that aren't in MAPPING_DICT unchanged, use MAPPING_DICT.get(k,k)
instead. Other corner cases include many-to-one mappings, and incomplete
mappings where a replacement key is also an unmapped old key.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Sep 7, 5:03 pm, Marc 'BlackJack' Rintsch <[EMAIL PROTECTED]> wrote: > On Mon, 08 Sep 2008 07:34:55 +1000, James Mills wrote: > > This is the strangest post I've seen > > since I've joined this list (only > > recently). What the ? > > Yeah, castironpi sometimes doesn't make much sense. Maybe because it's a > bot!? :-) > > Ciao, > Marc 'BlackJack' Rintsch No, I'm legit, and I believe my complaint is. That's all I can guarantee anyway. While I'm still not a vet on Usenet, I'm still disappointed so far. Though I should be flattered for my logic to be ever compared to an A.I.'s. Maybe the ideas are not that groundbreaking, but they still have been dropped instead of critiqued. Problem. -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
+1 Bot -- http://mail.python.org/mailman/listinfo/python-list
Long lines [was Re: __builtins__ magic behavior]
Gabriel, could I please ask you to configure your news-reader software or editor to limit the length of each line of your posts to 70 characters wide, as per the common standard for email and Usenet? Your lines are significantly longer than that, including one single line which is 325 characters wide. That forces a lot of backwards and forwards scrolling to read your posts. Thank you. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
Marc 'BlackJack' Rintsch wrote: Yeah, castironpi sometimes doesn't make much sense. Maybe because it's a bot!? :-) if so, they sure don't make c.l.py bots like they used to, do they? -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Sep 8, 7:51 am, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote:
> Hello...
>
> I have a dict of key/values and I want to change the keys in it, based
> on another mapping dictionary. An example follows:
>
> MAPPING_DICT = {
> 'a': 'A',
> 'b': 'B',
>
> }
>
> my_dict = {
> 'a': '1',
> 'b': '2'
>
> }
>
> I want the finished my_dict to look like:
>
> my_dict = {
> 'A': '1',
> 'B': '2'
>
> }
>
> Whereby the keys in the original my_dict have been swapped out for the
> keys mapped in MAPPING_DICT.
>
> Is there a clever way to do this, or should I loop through both,
> essentially creating a brand new dict?
>
Is this homework?
There seems to be an implicit assumption in the answers so far that
your mapping is a 1:1 mapping of all possible input keys.
If it doesn't include all possible input keys, answers will crash with
a KeyError. If there are any many:1 elements in the mapping (for
example, {'a': 'A', 'b': 'A'}), lossage happens. You may wish to code
in some checks for this.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Mon, Sep 8, 2008 at 8:37 AM, John Machin <[EMAIL PROTECTED]> wrote:
> Is this homework?
I hope it's not - or I'll be quite annoyed :)
> There seems to be an implicit assumption in the answers so far that
> your mapping is a 1:1 mapping of all possible input keys.
>
> If it doesn't include all possible input keys, answers will crash with
> a KeyError. If there are any many:1 elements in the mapping (for
> example, {'a': 'A', 'b': 'A'}), lossage happens. You may wish to code
> in some checks for this.
You are quite right! But then he/she didn't
ask for this right ? :)
cheers
James
--
--
-- "Problems are solved by method"
--
http://mail.python.org/mailman/listinfo/python-list
Read and write binary data
Hi guys, I am new to Python, and thinking about migrating to it from matlab as it is a really cool language. Right now, I am trying to figure out how to control read and write binary data, like 'formatted','stream','big-endian','little-edian' etc.. as in fortran. I googled, but can not find a clear answer. Anyone has clue where can I learn it? Thanks!! Jinbo -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Sep 8, 8:36 am, Fredrik Lundh <[EMAIL PROTECTED]> wrote: > Marc 'BlackJack' Rintsch wrote: > > Yeah, castironpi sometimes doesn't make much sense. Maybe because it's a > > bot!? :-) > > if so, they sure don't make c.l.py bots like they used to, do they? > > That's correct. This one seems to have an anger management module :-) -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Mon, 08 Sep 2008 07:34:55 +1000, James Mills wrote: > Hi, > > This is the strangest post I've seen > since I've joined this list (only > recently). What the ? Oh don't mind castironpi, many people think he's an IRC bot with some experimental AI features that escaped onto Usenet *grins*. If you think that post of his was strange, you haven't seen anything yet. Many people have kill-filed him, and never even see his posts. A word to castironpi: you just suggested you will pester the list to get a response. It's behaviour like that which gets you kill-filed. If you would spend one tenth of the effort that you spend on understand Python on understanding human psychology, you will probably get on with others much better and find fewer people claiming you're a bot. Even if you yourself don't understand how others behave and expect you to behave, think of it as an intellectual puzzle: how can I fool the strange hairless apes into accepting me into their herd? -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: doctest not seeing any of my doc tests
On Sun, 07 Sep 2008 15:51:01 +0200, Fredrik Lundh wrote: > Steven D'Aprano wrote: > >> I have a function in my module: >> >> def selftest(verbose=False): >> import doctest >> doctest.testmod(verbose=verbose) > > what happens if you change the above to > >def selftest(verbose=False): >import doctest, yourmodule >doctest.testmod(yourmodule, verbose=verbose) > > (where yourmodule is the name of your module, obviously) Well, that certainly fixed the problem, thanks. It now correctly runs all my doctests. But I don't understand why a bare doctest.testmod() works when you run it non-interactively, but fails when run interactively. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Sep 8, 8:42 am, "James Mills" <[EMAIL PROTECTED]> wrote:
> On Mon, Sep 8, 2008 at 8:37 AM, John Machin <[EMAIL PROTECTED]> wrote:
> > There seems to be an implicit assumption in the answers so far that
> > your mapping is a 1:1 mapping of all possible input keys.
>
> > If it doesn't include all possible input keys, answers will crash with
> > a KeyError. If there are any many:1 elements in the mapping (for
> > example, {'a': 'A', 'b': 'A'}), lossage happens. You may wish to code
> > in some checks for this.
>
> You are quite right! But then he/she didn't
> ask for this right ? :)
>
What do you mean by "this right"? Perhaps the Divine Right of OPs,
managers, examiners, business analysts, etc never to give a complete
spec up front and never to contemplate the consequences of Murphy's
Law?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python and M2Crypto question
On Sep 7, 11:07 pm, Bojan Mihelac <[EMAIL PROTECTED]> wrote: > Hi all! > > I am trying to install M2Crypto to work on OSX10.5 apache > (mod_python). Error I receive: > > Error was: dlopen(/Library/WebServer/eggs/M2Crypto-0.18.2-py2.5- > macosx-10.5-i386.egg-tmp/M2Crypto/__m2crypto.so, 2): no suitable image > found. Did find: > /Library/WebServer/eggs/M2Crypto-0.18.2-py2.5-macosx-10.5-i386.egg- > tmp/M2Crypto/__m2crypto.so: no matching architecture in universal > wrapper > > I guess that have to do something with x64 architecture but I am > stucked and not able to find a way and to make this work. M2Crypto lib > works good stand alone. See: http://code.google.com/p/modwsgi/wiki/InstallationOnMacOSX#Missing_Code_For_Architecture This is mod_wsgi documentation, but same issue applies to mod_python. Graham -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Sun, 07 Sep 2008 15:59:52 -0700, John Machin wrote:
> On Sep 8, 8:42 am, "James Mills" <[EMAIL PROTECTED]> wrote:
>> On Mon, Sep 8, 2008 at 8:37 AM, John Machin <[EMAIL PROTECTED]>
>> wrote:
>
>> > There seems to be an implicit assumption in the answers so far that
>> > your mapping is a 1:1 mapping of all possible input keys.
>>
>> > If it doesn't include all possible input keys, answers will crash
>> > with a KeyError. If there are any many:1 elements in the mapping (for
>> > example, {'a': 'A', 'b': 'A'}), lossage happens. You may wish to code
>> > in some checks for this.
>>
>> You are quite right! But then he/she didn't ask for this right ? :)
>>
>>
> What do you mean by "this right"? Perhaps the Divine Right of OPs,
> managers, examiners, business analysts, etc never to give a complete
> spec up front and never to contemplate the consequences of Murphy's Law?
I *think* that what James Mills meant was:
"But then he/she didn't ask for this comma right?"
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Mon, Sep 8, 2008 at 8:59 AM, John Machin <[EMAIL PROTECTED]> wrote: > What do you mean by "this right"? Perhaps the Divine Right of OPs, > managers, examiners, business analysts, etc never to give a complete > spec up front and never to contemplate the consequences of Murphy's > Law? Now you're being silly. -- -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Sep 7, 5:45 pm, Steven D'Aprano <[EMAIL PROTECTED] cybersource.com.au> wrote: > On Mon, 08 Sep 2008 07:34:55 +1000, James Mills wrote: > > Hi, > > > This is the strangest post I've seen > > since I've joined this list (only > > recently). What the ? > > Oh don't mind castironpi, many people think he's an IRC bot with some > experimental AI features that escaped onto Usenet *grins*. If you think > that post of his was strange, you haven't seen anything yet. Many people > have kill-filed him, and never even see his posts. > > A word to castironpi: you just suggested you will pester the list to get > a response. It's behaviour like that which gets you kill-filed. If you > would spend one tenth of the effort that you spend on understand Python > on understanding human psychology, you will probably get on with others > much better and find fewer people claiming you're a bot. > > Even if you yourself don't understand how others behave and expect you to > behave, think of it as an intellectual puzzle: how can I fool the strange > hairless apes into accepting me into their herd? > > -- > Steven First, gauge their persistence tolerance. Some people are not persistent enough. I don't want to annoy you, and I want to show interest, but of course no more than I actually feel. Are my standards too low, or too high? Second, debate the reverse psychology tack. Claim I'm a bot to shake their belief? Or call them bots? Perhaps they are. Bots with cooties. Yes. -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On 7 Sep, 23:00, castironpi <[EMAIL PROTECTED]> wrote: > I am concerned by the lack of follow-through on some responses to > recent ideas I have described. Do I merely have a wrong understanding > of group policy? I think some people have taken exception to your contributions previously, which I believe exhibits a certain degree of shortsightedness on their part, considering for example the recent thread which brought up just-in-time compilation techniques where there were pretty valid reasons for keeping the thread going. Certainly, it wasn't as if the level of discussion was stuck at basic contradiction or mudslinging, and even if reading the different papers on the topic might help an inquirer on the matter, there's certainly nothing wrong with seeking guidance over which papers might be the best ones, nor with seeking some kind of context for that work within the realm of Python implementations, especially given the recent glut of news on virtual machine improvements for other dynamic languages. > Is it a good policy (defined with respect to the > future of Python and the welfare of humans at large) if so? Is there > a serious lack of diligence, or should I merely take more initiative, > and ignore charges of 'pestering'? (Warning, moderately deep outside > social issues on table too.) I'm no expert on getting other people to embrace ideas, but here's my advice anyway. If you have an idea and can describe it coherently, please do so; this won't guarantee positive responses, but there may be people out there who feel that you're onto something. If the idea has merit - generally, the most reliable way to know involves you personally experiencing difficulties in a problem area where the idea in question promises to alleviate some of those difficulties - then by developing that idea, typically producing something that others can try out, people will know that you mean business. Alternatively, people might point you to existing work that will address the problems you're having, saving you the bother of having to write a load of code to enact that idea of yours. You can be lucky and have people chasing you down over what you've produced, but I'd argue that most of the time, for any given idea which becomes a project, you'll have a few people interested in what you've done, but the motivation for continuing will be something that will depend on yourself and your own needs. You have to accept that even if you think that people (and Python) might be well served in listening to what you have to say, that message may go unheard. Once upon a time, the BDFL and the most central core developers used to read comp.lang.python and ideas about Python's future were exchanged readily. Today, all lobbying takes place on the python-dev/ 3000/ideas mailing lists, but those lists are more conservative with regard to contributions than comp.lang.python (python-list). Perhaps as a consequence, the divide between those steering the language and those using it has grown: "producers" use the aforementioned lists, "consumers" argue with each other on the newsgroup, and it might be in the release notes that you learn about happenings that previously would have been reported more widely elsewhere. Certainly, influencing the future of Python, at least officially, is a lot more hard work than it used to be. One may decide to worry about this, along with matters like how Python will remain able to compete with other languages and platforms. I regard the future development of Python as a process which may not necessarily serve my interests, but since the community around Python is so much larger and more diverse than those following every last Python 3.0 commit, I see no need to become agitated by the direction of the language developers. Since Python is Free Software one has, after all, a lot of flexibility when deciding who to associate with and who to influence, and it is ultimately only through trying to achieve things with the technology that one's priorities (or the things one should be worrying about) emerge. For me, then, influencing Python 3.x isn't a priority since I have enough to be thinking about and working on, and I wonder if I'll ever do anything with Python 3.x anyway. So, I suppose, the message is this: follow your own interests, make contributions in the ways that make sense to you, seek contact with like-minded developers in groups which might be remote from mainstream Python development (find an appropriate, potentially specialised audience); these things will define any need you may have to influence others. Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Sep 7, 3:13�pm, "Gabriel Genellina" <[EMAIL PROTECTED]> wrote: > En Sun, 07 Sep 2008 14:30:09 -0300, Mensanator <[EMAIL PROTECTED]> escribi�: > > > > > Actualy, I already get the behaviour I want. sum([1,None]) > > throws an exception. I don't see why sum([]) doesn't throw > > an exception also (I understand that behaviour is by design, > > I'm merely pointing out that the design doesn't cover every > > situation). > [...] > > Exactly. That's why I would prefer sum([]) to raise an > > exception instead of giving a false positive. > > The built in behavior can't be good for every usage. Nobody prevents you from > defining yoru own function tailored to your own specs, like this: > > def strict_sum(items): > � � items = iter(items) > � � try: > � � � � first = items.next() > � � except StopIteration: > � � � � raise ValueError, "strict_sum with empty argument" > � � return sum(items, first) > > Tweak as needed. Based on other posts I believe your Python skills are enough > to write it on your own, so I don't see why you're complaining so hard about > the current behavior. I'm not complaining about the behaviour anymore, I just don't like being told I'm wrong when I'm not. But I think I've made my point, so there's no point in harping on this anymore. > > -- > Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Sep 7, 11:28 pm, "Eric Wertman" <[EMAIL PROTECTED]> wrote: > +1 Bot I think it's like duck typing: it doesn't matter whether he's actually a bot, only whether he behaves like one. -- http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Sep 7, 1:17�pm, Patrick Maupin <[EMAIL PROTECTED]> wrote: > On Sep 7, 12:30�pm, Mensanator <[EMAIL PROTECTED]> wrote: > > > On Sep 6, 11:05 pm, Steven D'Aprano <[EMAIL PROTECTED] > > > Sheesh. That's not a problem, because Python is not trying to be a > > > dialect of SQL. > > > And yet, they added a Sqlite3 module. > > Does that mean that, because there is an 'os' module, Python is trying > to compete with Linux and Windows? I wasn't thinking "compete", rather "complement". Python obviously wants to be a player in the SQL market, so you would think it would be in Python's interest to know how SQL behaves, just as it's in Python's interest for the os module to know how BOTH Linnux and Windows work. > > This is starting to feel like a troll, It wasn't intended to be. > but JUST IN CASE you are really > serious about wanting to get work done with Python, rather than > complaining about how it is not perfect, Things never change if no one ever speaks up. > I offer the following snippet > which will show you how you can test the results of a sum() to see if > there were any items in the list: Thanks. I'll drop this from this point on. > > >>> class MyZero(int): > > ... � � pass > ... > > > > >>> zero = MyZero() > >>> x=sum([], zero) > >>> isinstance(x,MyZero) > True > >>> x = sum([1,2,3], zero) > >>> isinstance(x,MyZero) > False- Hide quoted text - > > - Show quoted text - -- http://mail.python.org/mailman/listinfo/python-list
Re: Updating python dictionary
On Sep 7, 3:37 pm, John Machin <[EMAIL PROTECTED]> wrote:
> On Sep 8, 7:51 am, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote:
>
>
>
> > Hello...
>
> > I have a dict of key/values and I want to change the keys in it, based
> > on another mapping dictionary. An example follows:
>
> > MAPPING_DICT = {
> > 'a': 'A',
> > 'b': 'B',
>
> > }
>
> > my_dict = {
> > 'a': '1',
> > 'b': '2'
>
> > }
>
> > I want the finished my_dict to look like:
>
> > my_dict = {
> > 'A': '1',
> > 'B': '2'
>
> > }
>
> > Whereby the keys in the original my_dict have been swapped out for the
> > keys mapped in MAPPING_DICT.
>
> > Is there a clever way to do this, or should I loop through both,
> > essentially creating a brand new dict?
>
> Is this homework?
>
> There seems to be an implicit assumption in the answers so far that
> your mapping is a 1:1 mapping of all possible input keys.
>
> If it doesn't include all possible input keys, answers will crash with
> a KeyError. If there are any many:1 elements in the mapping (for
> example, {'a': 'A', 'b': 'A'}), lossage happens. You may wish to code
> in some checks for this.
Thats exactly why I did an explicit check in my post, so as to make
sure that such a collision could not occur. It would seem that
something along what I posted would be safer, if less elegant, than
the others.
Cheers, MK
--
http://mail.python.org/mailman/listinfo/python-list
Re: max(), sum(), next()
On Sep 7, 2:17�pm, Dennis Lee Bieber <[EMAIL PROTECTED]> wrote: > On Sun, 7 Sep 2008 10:30:09 -0700 (PDT), Mensanator <[EMAIL PROTECTED]> > declaimed the following in comp.lang.python: > > > On Sep 6, 11:05?pm, Steven D'Aprano <[EMAIL PROTECTED] > > cybersource.com.au> wrote: > > > > Sheesh. That's not a problem, because Python is not trying to be a > > > dialect of SQL. > > > And yet, they added a Sqlite3 module. > > � � � � Which is an interface TO an embedded/stand-alone SQL-based RDBM > engine; it does not turn Python into a dialect of SQL -- Python does not > process the SQL, it gets passed to the engine for SQL data processing. But that's only half the story. The other half is data returned as a result of SQL queries. And that's something Python DOES process. And sometimes that processed data has to be inserted back into the database. We certainly don't want Python to process the data in a way that the database doesn't expect. When I see a potential flaw (such as summing an empty list to 0), should I just keep quiet about it, or let everyone know? Well, now they know, so I'll shut up about this from now on, ok? > -- > � � � � Wulfraed � � � �Dennis Lee Bieber � � � � � � � KD6MOG > � � � � [EMAIL PROTECTED] � � � � � � [EMAIL PROTECTED] > � � � � � � � � HTTP://wlfraed.home.netcom.com/ > � � � � (Bestiaria Support Staff: � � � � � � � [EMAIL PROTECTED]) > � � � � � � � � HTTP://www.bestiaria.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Read and write binary data
On Sep 7, 5:41 pm, Mars creature <[EMAIL PROTECTED]> wrote: > Hi guys, > I am new to Python, and thinking about migrating to it from matlab > as it is a really cool language. Right now, I am trying to figure out > how to control read and write binary data, like > 'formatted','stream','big-endian','little-edian' etc.. as in fortran. > I googled, but can not find a clear answer. Anyone has clue where can > I learn it? Thanks!! > Jinbo Start by looking at the array module. Regards, Pat -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
Paul Boddie <[EMAIL PROTECTED]> writes: > On 7 Sep, 23:00, castironpi <[EMAIL PROTECTED]> wrote: > > I am concerned by the lack of follow-through on some responses to > > recent ideas I have described. Do I merely have a wrong > > understanding of group policy? > > I think some people have taken exception to your contributions > previously, which I believe exhibits a certain degree of > shortsightedness on their part […] For my part, I find those posts a mammoth waste of my time, since they're shrouded in language so difficult to parse that I can't see what they're supposed to be saying in a reasonable amount of time. So, I consider it more valuable to never see those posts; if someone else can find a gem of wisdom in any of them that's significantly valuable, presumably I'll find out by some other means than attempting to read those posts myself. This is not intended as any kind of offense to the author, nor to anyone not fluent in written English; it's merely a choice I make as to how I will spend my time. -- \ “No wonder I'm all confused; one of my parents was a woman, the | `\ other was a man.” —Ashleigh Brilliant | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Use BeautifulSoup to delete certain tag while keeping its content
Jackie Wang wrote: Dear all, I have the following html code: Center Bank Los Angeles, CA Salisbury Bank and Trust Company Lakeville, CT How should I delete the 'font' tags while keeping the content inside? See the BeautifulSoup documentation. Find the font tags with findAll, make a list, then go in and use "extract" and "replaceWith" appropriately. John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Sep 7, 7:34 pm, MRAB <[EMAIL PROTECTED]> wrote: > On Sep 7, 11:28 pm, "Eric Wertman" <[EMAIL PROTECTED]> wrote: > > > +1 Bot > > I think it's like duck typing: it doesn't matter whether he's actually > a bot, only whether he behaves like one. Do you support the bot interface and methods? -- http://mail.python.org/mailman/listinfo/python-list
Subprocess freezes when piping from stdout.
Hi All, I'm using subprocess.Popen to run a C++ compiler and have set stdout = PIPE. The exact line of code that I am using is: process = Popen(command, stdout=PIPE) status = process.wait() This works fine until a large amount of data is written to stdout. When this occurs, my python program seems to freeze. It will no longer run or respond to Ctrl-C. I am assuming that it is stuck waiting for the process to end, but I'm not sure why this should take so long (I have left it running for hours and it never ended) At the moment the code is being executed on a Win32 environment. Is anyone aware of why this might be occurring, or of any ways around this? Does the PIPE implementation in Win32 have a maximum buffer size? Regards, James McGill -- http://mail.python.org/mailman/listinfo/python-list
Re: Not fully understanding the role of Queue.task_done()
Fredrik Lundh <[EMAIL PROTECTED]> wrote: > (btw, I've always thought that Python was all about making it easy to > express the solution to a given problem in code, not to let you write > programs without using your brain. when did that change?) The day Google App Engine was opened up to developers, I believe. -- http://mail.python.org/mailman/listinfo/python-list
Re: Subprocess freezes when piping from stdout.
James McGill wrote: Is anyone aware of why this might be occurring, or of any ways around this? Does the PIPE implementation in Win32 have a maximum buffer size? pipes always have a limited buffer size, on all platforms. you're supposed to read data from them as it arrives (e.g. by explicitly reading from the "stdout" attribute, or by calling "communicate"). if you cannot do that, bind the channel to a file, not a pipe. -- http://mail.python.org/mailman/listinfo/python-list
Re: lacking follow-through
On Sep 8, 7:00 am, castironpi <[EMAIL PROTECTED]> wrote: > I am concerned by the lack of follow-through on some responses to > recent ideas I have described. Do I merely have a wrong understanding > of group policy? [snip] Perhaps the wrong idea of what the group is. I would have thought that if one had a sufficiently developed idea and wanted to have it / formally/ rejected, rather than merely sniped at, then writting a PEP would be more apposite than posting to c.l.py. It's fine to post your not sufficiently developed ideas here merely to have them discussed. But I don't know what makes you feel that you, or your ideas, are /entitled/ to any response at all, much less "follow-through." -- http://mail.python.org/mailman/listinfo/python-list
Spotlight Searching in Python - Mac OSX
Hi all, I'm having some issues getting a spotlight search to work
similar to the program demonstrated here:
http://pyobjc.sourceforge.net/examples/pyobjc-framework-Cocoa/AppKit/PredicateEditorSample/
Here is my class, complete with the code I am trying to use it with at
the end.
import objc, sys, os, osax, time
from Foundation import *
from ScriptingBridge import *
from appscript import *
class SystemBridge(NSObject):
"""Class to use the scripting bridge to interact with the system"""
_hideapp = objc.ivar(u"hideapp")
_volume = objc.ivar(u"volume")
_filename = objc.ivar(u"filename")
_filetype = objc.ivar(u"filetype")
_auth = objc.ivar(u"auth")
_logout = objc.ivar(u"logout")
query = objc.ivar(u"query")
StdAdditions = osax.ScriptingAddition()
def init(self):
super(SystemBridge, self).init()
# create and initalize our query
self.query = NSMetadataQuery.alloc().init()
# setup our Spotlight notifications
nf = NSNotificationCenter.defaultCenter()
nf.addObserver_selector_name_object_(self,
'queryNotification:', None, self.query)
# XXX: this framework isn't wrapped yet!
self.query.setSortDescriptors_([NSSortDescriptor.alloc().initWithKey_ascending_('kMDItemDisplayName',
True)])
self.query.setDelegate_(self)
return self
def hideApplication_(self, _hideapp):
app(u'System Events').processes[_hideapp].visible.set(False)
def loadResultsFromQuery_(self, notif):
results = notif.object().results()
NSLog("search count = %d", len(results))
# iterate through the array of results, and match to the
existing stores
for item in results:
nameStr = item.valueForAttribute_('kMDItemDisplayName')
print nameStr
def queryNotification_(self, note):
# the NSMetadataQuery will send back a note when updates are
happening.
# By looking at the [note name], we can tell what is happening
if note.name() ==
NSMetadataQueryDidStartGatheringNotification:
# the query has just started
NSLog("search: started gathering")
elif note.name() ==
NSMetadataQueryDidFinishGatheringNotification:
# at this point, the query will be done. You may recieve
an update
# later on.
NSLog("search: finished gathering");
self.loadResultsFromQuery_(note)
elif note.name() ==
NSMetadataQueryGatheringProgressNotification:
# the query is still gathering results...
NSLog("search: progressing...")
elif note.name() == NSMetadataQueryDidUpdateNotification:
# an update will happen when Spotlight notices that a file
as
# added, removed, or modified that affected the search
results.
NSLog("search: an update happened.")
def spotlightFriendlyPredicate_(self, predicate):
if predicate == NSPredicate.predicateWithValue_(True) or
predicate == NSPredicate.predicateWithValue_(False):
return False
elif isinstance(predicate, NSCompoundPredicate):
type = predicate.compoundPredicateType()
cleanSubpredicates = []
for dirtySubpredicate in predicate.subpredicates():
cleanSubpredicate =
self.spotlightFriendlyPredicate_(
dirtySubpredicate)
if cleanSubpredicate:
cleanSubpredicates.append(cleanSubpredicate)
if len(cleanSubpredicates) == 0:
return None
else:
if len(cleanSubpredicates) == 1 and type !=
NSNotPredicateType:
return cleanSubpredicates[0]
else:
return
NSCompoundPredicate.alloc().initWithType_subpredicates_(type,
cleanSubpredicates)
else:
return predicate
def createNewSearchForPredicate_(self, predicate):
# Format search file type
thePredicate = NSPredicate.predicateWithFormat_(
"(kMDItemContentType =
'com.apple.iwork.keynote.key')")
tempPredicate = NSPredicate.predicateWithFormat_(
"(kMDItemDisplayName IN[c] 'preso')")
predicate = NSCompoundPredicate.andPredicateWithSubpredicates_(
[thePredicate, tempPredicate])
self.query.setPre
firefox timestamp
Hi all, I don't know if this question will fit on this section, any way my query is , i have used one script demork.py to extract details from Firefox history.dat file and now the problem is how to convert the TIMESTAMP given by that to normal date and time. example timestams are like this, 1202919771609375 1213874676203125 1215693263859375 i have used datetime module for this but it gave me error >>> import datetime >>> datetime.datetime.fromtimestamp(1215693263859375) Traceback (most recent call last): File "", line 1, in datetime.datetime.fromtimestamp(1215693263859375) ValueError: timestamp out of range for platform time_t please help me to convert this ? -- http://mail.python.org/mailman/listinfo/python-list
