Failing on string exceptions in 2.4
Reading the Python docs, it looks like string exceptions will be a DeprecationWarning in Python 2.5. Is there any way to make them so in 2.4? Now how about if I want to turn all DeprecationWarnings into compile-time errors? Is there some way to do this? End goal being that string exceptions would cause compilation to fail. A few times now, I've found myself doing class SomeClass: """docstring""" pass raise SomeClass, "Some description" and I've gotten a weird compiler error about the constructor for SomeClass. I'd prefer it just to fail there and not let me raise an exception that isn't subclassed beneath Exception. -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: Html parser
On Fri, Jun 15, 2007 at 07:11:56AM -0700, HMS Surprise wrote: > Could you recommend an html parser that works with python (jython > 2.2)? I'm new here, but I believe BeautifulSoup is the canonical answer: http://www.crummy.com/software/BeautifulSoup/ -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
PEP 3107 and stronger typing (note: probably a newbie question)
Before I ask anything, let me note that this is surely an old question that has inspired its share of flame wars; I'm new to Python, but not new to how Internet discussions work. So if there's a canonical thread or web page that documents the whole battle, feel free to point me to it. Reading [1], I wonder: why isn't the compiler making better use of (purely optional) type labeling? Why not make a compiler directive so that a) it will check the types of all my arguments and return values, and maybe even b) do some type inference up the call stack? E.g., def( Class1 arg1, Class2 arg2, ..., ClassN argN ): someStuff() would check the types of the arguments, whereas def( arg1, arg2, ..., argN): someStuff() would not? I.e., if I *want* strong static type-checking, why shouldn't I be able to get it? Is it that allowing this as a compile-time option would mess up too many knobs to make it optional? Again, probably an old debate. I'd like to know why Guido's decided that not only is strong static typing productivity-reducing [2], but that it should be *forbidden*. [1] - http://www.python.org/dev/peps/pep-3107/ [2] - http://www.artima.com/intv/strongweakP.html -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 3107 and stronger typing (note: probably a newbie question)
On Wed, Jun 20, 2007 at 12:59:28PM -0700, [EMAIL PROTECTED] wrote: > Then you should use another language. This is what I meant about knowing how Internet discussions go. -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 3107 and stronger typing (note: probably a newbie question)
On Wed, Jun 20, 2007 at 09:41:09PM +0100, Michael Hoffman wrote: > If you asked Java programmers why you couldn't turn *off* Java's static > type checking if you wanted to, you'd probably get a similar response. Perhaps it would help for me to explain what I'd like. Under both Perl and Python, I've found myself having/wanting to write things like so: def my_func( int_arg, str_arg ): try: int_arg = int( int_arg ) str_arg = str( str_arg ) except ValueError: sys.stderr.write( "Args are not of the right type\n" ) sys.exit(1) Granted, in a dynamic language we won't always (maybe "won't often") have a situation where the types are known this well at compile time. But sometimes we will. And it would be nice to catch these before the program even runs. So my question is: would bolting on "static type checking when we can, no type checking when we can't" be too much to ask? My reason for asking initially was that the PEP adds all kinds of information to the function prototype -- e.g. (quoting from there) def foobar( a: Integer, b: Sequence ) -> String: so why not, I reasoned, use this information at compile time? Of course I understand the virtue of writing code with good doctests, etc. But my question is why we can't get some more static typing as well. Given the tools that'll be in Python 3.0, that doesn't seem unreasonable to ask. Apparently it is unreasonable. I'm sorry I asked. -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: strip() 2.4.4
On Thu, Jun 21, 2007 at 06:23:01AM -0700, Nick wrote: > Why is there a apostrophe still at the end? Is it possible that you actually have whitespace at the end of the line? So then strip() is looking for an apostrophe at the end of the line, not finding it, and therefore not stripping it? -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: strip() 2.4.4
On Thu, Jun 21, 2007 at 01:42:03PM +, linuxprog wrote: > that should work for you ? I reproduced the original poster's problem by adding one extra space after the final "'" on each line. I'd vote that that's the problem. -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 3107 and stronger typing (note: probably a newbie question)
On Thu, Jun 21, 2007 at 03:55:48PM +0200, Bjoern Schliessmann wrote: > I agree. I also notice that (rather newbie-) OPs with not-so-simple > questions are easily offended by technical answers. I'd love to > know why. One doesn't like to get meta on such things, as so often happens, so I'll be brief. The way I read my original post was like so: "I know lots of people have probably had a similar question, so please point me to a canonical answer is there is one. So here's the question...". To me, an appropriate answer there is, "That's a good question, and many people have asked it. Here's why it's unlikely that static type-checking makes sense in the context of Python, and why it couldn't just be added in pieces." We got there eventually, but only after what seemed to me to be a bout of rudeness. Now, maybe my own followup clarified something that I should have included in the original. "Use another language" is not a technical answer. "Python could not adopt static typing without substantially changing the language and destroying what everyone loves about it, and here are examples of where the problem shows up" is. But I've just gone meta, so I'll stop. -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 3107 and stronger typing (note: probably a newbie question)
On Thu, Jun 21, 2007 at 10:11:57AM -0400, Stephen R Laniel wrote: > "Use another language" is not a technical answer. "Python > could not adopt static typing without substantially changing > the language and destroying what everyone loves about it, > and here are examples of where the problem shows up" is. The best dynamic-versus-static-typing discussion I've ever seen, by the way, was Mark-Jason Dominus's (he of "Higher-Order Perl"): http://perl.plover.com/yak/typing/notes.html -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: Tailing a log file?
On Fri, Jun 22, 2007 at 11:46:56AM -0700, Evan Klitzke wrote: > I checked the source code for tail and they actually poll the file by > using fstat and sleep to check for changes in the file size. This > didn't seem right so I thought about it more and realized I ought to > be using inotify. So I guess I answered my own question. I've not thought about it much, but how about using Twisted? Something like the LineReceiver class seems appropriate here. http://twistedmatrix.com/documents/current/api/twisted.protocols.basic.LineReceiver.html -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: newbie tcp/ip question
On Sun, Jun 24, 2007 at 02:52:25PM -0500, Zachary Manning wrote: > I want to send some hex characters as a string literal to port 7142 and > to a specific ip address. How do I do that in python? Does this cover what you want to do? http://docs.python.org/lib/socket-example.html -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: server wide variables
On Mon, Jun 25, 2007 at 03:29:25PM -, Jay Sonmez wrote: > I want to be able to save some server variables as long as Apache runs > on the server (mod_python). > > How is that possible in Python? Would setting environment variables help you? You'd use os.environ. http://docs.python.org/lib/os-procinfo.html -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: finding an element in a string
On Mon, Jun 25, 2007 at 04:09:50PM -0400, Miguel Oliveira wrote: > But that, obviously, will only respond "good" when one writes "fine". I was > looking for a way for the program to respond "good" to any sentence that would > contain the word "fine" in it. What you want is a regular-expression match. Are you familiar with regexes? The relevant Python documentation is here (for the module 're'): http://docs.python.org/lib/module-re.html though I find it's not particularly easy reading. The Friedl book recommended in there is the canonical source about regexes, and it is indeed a great book. You should read some manpages first, though. Just google for 'regular expressions' and you'll find all that you need. In the meantime, what you want is something like if re.search( r'fine', x ): # things one does if the user said 'fine' Alternately, you could just use rfind(): http://docs.python.org/lib/string-methods.html but regexes are a good tool to get to know. They're overused (particularly in Perl), but this is just the sort of task they're good for. -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: Help needed in Handling HTML file
On Tue, Jun 26, 2007 at 09:42:37AM -0500, senthil arasu wrote: > Right now Iam handling HTML files using Python. > Is there any modules to support HTML parsing and rendering ? > or suggest me any other way to support HTML. Parsing: BeautifulSoup http://www.crummy.com/software/BeautifulSoup/ Rendering: not sure. If worse came to worst, you could always call out to 'w3m -dump' using system(). How sophisticated do you want your rendering to be? Other people on this last may well know of ways to fully render a page, including graphics and JavaScript and whatever else, using a scriptable Python object; I do not. -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: Return name of caller function?
On Mon, Jun 25, 2007 at 06:27:29PM -0700, Matthew Peter wrote: > For example, how do I get this to work? > > def func(): > print "This is", __?__ > return __caller__ > > def echo(): > print "This is ", __?__ > return func() inspect is your friend: http://docs.python.org/lib/inspect-stack.html -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 3107 and stronger typing (note: probably a newbie question)
On Wed, Jun 27, 2007 at 01:44:17PM +0200, Bruno Desthuilliers wrote: > Indeed - static typing is for compilers, not for programmers. When done well, static typing helps the programmer -- just like writing good unit tests. It's not a magic bullet, but it can help. I'd like to point again to Mark-Jason Dominus's explanation of how strong static typing can be done well: http://perl.plover.com/yak/typing/notes.html The example toward the end of how ML actually spots an infinite loop at compile time seems to me to be "for programmers" rather than "for compilers." -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: PEP 3107 and stronger typing (note: probably a newbie question)
On Wed, Jun 27, 2007 at 04:03:39PM +0200, Bruno Desthuilliers wrote: > Stephen, you may not know yet, but Python is *dynamic*. This defeats > almost all compile-time checking. Of what help would type inference be > when you can dynamically add/remove/replace attributes (including > methods and class) at runtime ? Heh. [Insert grimacing smile here] People on here have been ... ahhh ... *generous* about explaining that Python is dynamic, and hence that static typing doesn't make sense. I've got it. I merely passed along that MJD reference because you were making a point about what static typing is for in general (i.e., not specific to Python). I thought I'd give examples of how languages other than Python use it to good effect, and not just for compiler optimization. Cheers, Steve -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
Re: Return name of caller function?
On Wed, Jun 27, 2007 at 01:25:14PM -0700, Matthew Peter wrote:
> Parsing the stack's tuple to get those attributes didn't feel reliable or
> pythonic.
> I am likely overlooking something. Is there a brief example you could show me
> in the
> context of using inspect to accomplish the goal I outlined above? The goal is
> using
> a function and not a class. Thanks!
The code below doesn't do the trick for you?
#!/usr/bin/python
import inspect
def master():
print "I am the master"
slave()
def slave():
stack = inspect.stack()
caller = stack[1][3]
print "I am the slave; my caller was %s" % caller
def main():
master()
if __name__ == '__main__':
main()
--
Stephen R. Laniel
[EMAIL PROTECTED]
Cell: +(617) 308-5571
http://laniels.org/
PGP key: http://laniels.org/slaniel.key
--
http://mail.python.org/mailman/listinfo/python-list
Re: PEP 3107 and stronger typing (note: probably a newbie question)
On Thu, Jun 28, 2007 at 09:08:16AM +0200, Bruno Desthuilliers wrote: > You said ? I could link again to Mark-Jason Dominus, who writes that people often make the following inference: 1) C is strongly typed. 2) C's typing sucks. 3) Hence strong typing sucks. But I won't. It doesn't need to be a religious war. Why can't people just say "When strong typing is done and used well, it's a useful tool; when it's not, it's not"? -- Stephen R. Laniel [EMAIL PROTECTED] Cell: +(617) 308-5571 http://laniels.org/ PGP key: http://laniels.org/slaniel.key -- http://mail.python.org/mailman/listinfo/python-list
