Re: Line continuation and comments

Robert Latest wrote: > Paul Bryan wrote: >> Adding to this, there should be no reason now in recent versions of >> Python to ever use line continuation. Black goes so far as to state >> "backslashes are bad and should never be used": >> >

Re: Line continuation and comments

Paul Bryan wrote: > Adding to this, there should be no reason now in recent versions of > Python to ever use line continuation. Black goes so far as to state > "backslashes are bad and should never be used": > > https://black.readthedocs.io/en/stable/the_black_code_style/ future_style.html#using-

Re: Line continuation and comments

Edmondo Giovannozzi wrote: > Il giorno mercoledì 22 febbraio 2023 alle 09:50:14 UTC+1 Robert Latest ha > scritto: >> I found myself building a complicated logical condition with many ands and >> ors which I made more manageable by putting the various terms on individual >>

Line continuation and comments

I found myself building a complicated logical condition with many ands and ors which I made more manageable by putting the various terms on individual lines and breaking them with the "\" line continuation character. In this context it would have been nice to be able to add comments to lines terms

Why can't the pointer in a PyCapsule be NULL?

Hi all, the question is in the subject. I'd like the pointer to be able to be NULL because that would make my code slightly cleaner. No big deal though. -- https://mail.python.org/mailman/listinfo/python-list

Re: Why can't the pointer in a PyCapsule be NULL?

Stefan Ram wrote: > Robert Latest writes: >>the question is in the subject. I'd like the pointer to be able to be NULL >>because that would make my code slightly cleaner. No big deal though. > > In Usenet, it is considered good style to have all relevant > cont

Re: Need help with custom string formatter

Cameron Simpson wrote: > Stefan's code implements it's own format_field and falls back to the > original format_field(). That's standard subclassing practice, and worth > doing reflexively more of the time - it avoids _knowing_ that > format_field() just calls format(). > > So I'd take Stefan's

Re: Need help with custom string formatter

Stefan Ram wrote: [the solution] thanks, right on the spot. I had already figured out that format_field() is the one method I need, and thanks for the str.translate method. I knew that raking seven RE's across the same string HAD to be stupid. Have a nice weekend! -- https://mail.python.org/ma

Need help with custom string formatter

Hi all, I would like to modify the standard str.format() in a way that when the input field is of type str, there is some character replacement, and the string gets padded or truncated to the given field width. Basically like this: fmt = MagicString('<{s:6}>') print(fmt.format(s='Äußerst')) Outp

Re: Need help with custom string formatter

Hi Stefan, I have now implemented a version of this, works nicely. I have a few minor questions / remarks: > result += ' ' *( length - len( result )) Nice, I didn't know that one could multiply strings by negative numbers without error. > def __init__( self ): > super().__init_

Re: xml.etree and namespaces -- why?

Jon Ribbens wrote: > That's because you *always* need to know the URI of the namespace, > because that's its only meaningful identifier. If you assume that a > particular namespace always uses the same prefix then your code will be > completely broken. The following two pieces of XML should be unde

xml.etree and namespaces -- why?

Hi all, For the impatient: Below the longish text is a fully self-contained Python example that illustrates my problem. I'm struggling to understand xml.etree's handling of namespaces. I'm trying to parse an Inkscape document which uses several namespaces. From etree's documentation: If the

Re: for -- else: what was the motivation?

wrote: > I had another crazy thought that I AM NOT ASKING anyone to do. OK? > > I was wondering about a sort of catch method you could use that generates a > pseudo-signal only when the enclosed preceding loop exits normally as a > sort of way to handle the ELSE need without the use of a keyword

Re: What to use for finding as many syntax errors as possible.

Antoon Pardon wrote: > I would like a tool that tries to find as many syntax errors as possible > in a python file. I'm puzzled as to when such a tool would be needed. How many syntax errors can you realistically put into a single Python file before compiling it for the first time? -- https://m

Re: What to use for finding as many syntax errors as possible.

Michael F. Stemper wrote: > How does one declare a variable in python? Sometimes it'd be nice to > be able to have declarations and any undeclared variable be flagged. To my knowledge, the closest to that is using __slots__ in class definitions. Many a time have I assigned to misspelled class memb

Re: for -- else: what was the motivation?

Axy wrote: >> Also not really a justification for "shortest block first". Wanting >> some elaboration on that. What's the value in it? > > Well, the value is productivity. No need to save puzzles "what this > hanging else belongs to?" If you find yourself asking that question, the if-block is pro

Re: What to use for finding as many syntax errors as possible.

wrote: > Cameron, > > Your suggestion makes me shudder! Me, too > Removing all earlier lines of code is often guaranteed to generate errors as > variables you are using are not declared or initiated, modules are not > imported and so on. all of which aren't syntax errors, so the method should s

Re: for -- else: what was the motivation?

Grant Edwards wrote: > I've followed that advice for several decades. I find it much easier > to read code that's organized that way -- particularly when the > difference in block sizes is large (e.g. the first block is one line, > and the second is a a hundred). If any conditionally executed bloc

Re: for -- else: what was the motivation?

Chris Angelico wrote: > Yes, I'm aware that code readability becomes irrelevant for > short-duration projects. Beside the point. I'm wondering how important > it really is to have the shortest block first. I usually put the most expected / frequent / not negated block first if the whole if/else st

Re: Implementation of an lru_cache() decorator that ignores the first argument

Hi Chris and dh, thanks for your --as usually-- thoughtful and interesting answers. Indeed, when doing these web applications I find that there are several layers of useful, maybe less useful, and unknown caching. Many of my requests rely on a notoriously unreliable read-only database outside of m

Implementation of an lru_cache() decorator that ignores the first argument

Hi all, in a (Flask) web application I often find that many equal (SQLAlchemy) queries are executed across subsequent requests. So I tried to cache the results of those queries on the module level like this: @lru_cache() def query_db(db, args): # do the "expensive" query r

Re: SQLAlchemy: JSON vs. PickleType vs. raw string for serialised data

Loris Bennett wrote: > Thanks for the various suggestions. The data I need to store is just a > dict with maybe 3 or 4 keys and short string values probably of less > than 32 characters each per event. The traffic on the DB is going to be > very low, creating maybe a dozen events a day, mainly tr

Re: SQLAlchemy: JSON vs. PickleType vs. raw string for serialised data

Albert-Jan Roskam wrote: > The event may have arbitrary, but dict-like data associated with it, > which I want to add in the field 'info'.  This data never needs to be > modified, once the event has been inserted into the DB. > > What type should the info field have?  JSON, Pick

Re: Threading question .. am I doing this right?

Chris Angelico wrote: > I'm still curious as to the workload (requests per second), as it might still > be worth going for the feeder model. But if your current system works, then > it may be simplest to debug that rather than change. It is by all accounts a low-traffic situation, maybe one reques

Re: Best way to check if there is internet?

Chris Angelico wrote: > Every language learns from every other. Except Visual Basic, which didn't learn anything from anywhere, and all that can be learned from it is how not to do it. Ugh. -- https://mail.python.org/mailman/listinfo/python-list

Re: Threading question .. am I doing this right?

Greg Ewing wrote: > * If more than one thread calls get_data() during the initial > cache filling, it looks like only one of them will wait for > the thread -- the others will skip waiting altogether and > immediately return None. Right. But that needs to be dealt with somehow. No data is no data.

Re: Threading question .. am I doing this right?

Chris Angelico wrote: > Depending on your database, this might be counter-productive. A > PostgreSQL database running on localhost, for instance, has its own > caching, and data transfers between two apps running on the same > computer can be pretty fast. The complexity you add in order to do > you

Threading question .. am I doing this right?

I have a multi-threaded application (a web service) where several threads need data from an external database. That data is quite a lot, but it is almost always the same. Between incoming requests, timestamped records get added to the DB. So I decided to keep an in-memory cache of the DB records t

Re: Best way to check if there is internet?

Abdur-Rahmaan Janhangeer wrote: > I've got my answers but the 'wandering' a bit > on this thread is at least connected to the topic ^^. > > Last question: If we check for wifi or ethernet cable connection? > > Wifi sometimes tell of connected but no internet connection. > So it detected that there

Re: Best way to check if there is internet?

Abdur-Rahmaan Janhangeer wrote: > Well, nice perspective. > > It's a valid consideration, sound theory > but poor practicality according to me. On the contrary: It is absolutely the right and only way to do it. > It you view it like this then between the moment > we press run or enter key on the

Re: Long running process - how to speed up?

Shaozhong SHI wrote: > Can it be divided into several processes? I'd do it like this: from time import sleep from threading import Thread t = Thread(target=lambda: sleep(1)) t.run() # do your work here t.wait() -- https://mail.python.org/mailman/listinfo/python-list

Re: "undefined symbol" in C extension module

Dan Stromberg wrote: > Perhaps try: > https://stromberg.dnsalias.org/svn/find-sym/trunk > > It tries to find symbols in C libraries. > > In this case, I believe you'll find it in -lpythonx.ym Thanks! Found out that ldd produces many errors also with working python libraries. Turns out I tried to r

"undefined symbol" in C extension module

Hi guys, I've written some CPython extension modules in the past without problems. Now after moving to a new Archlinux box with Python3.10 installed, I can't build them any more. Or rather, I can build them but not use them due to "undefined symbols" during linking. Here's ldd's output when used o

Re: Advanced ways to get object information from within python

Julius Hamilton wrote: > dir(scrapy) shows this: > > ['Field', 'FormRequest', 'Item', 'Request', 'Selector', 'Spider', > '__all__', '__builtins__', '__cached__', '__doc__', '__file__', > '__loader__', '__name__', '__package__', '__path__', '__spec__', > '__version__', '_txv', 'exceptions', 'http',

Type annotation pitfall

Hi all, this just caused me several hours of my life until I could whittle it down to this minimal example. Simple question: Why is the x member of object "foo" modified by initializing "bar"? Obviously, initializing foo with None doesn't set foo.x at all. So I guess x stays a class property, not

Re: How to "cast" an object to a derived class?

Stefan Ram wrote: > Robert Latest writes: But how can I "promote" a >>given Opaque instance to the derived class? > > Sometimes, one can use containment instead of inheritance. Nah, doesn't work in my case. I'm trying to write a wrapper around xm

How to "cast" an object to a derived class?

Hi all, let's assume I'm using a module that defines some class "Opaque" and also a function that creates objects of that type. In my program I subclass that type because I want some extra functionality. But how can I "promote" a given Opaque instance to the derived class? Of course I could just cr

Re: Ad-hoc SQL query builder for Python3?

Rich Shepard wrote: > For those interested I've found a couple of possibilities: PyPika and > SQLbuilder. I'll be looking deeply into them to learn their capabilities. In case nobody mentioned it before, don't forget to take a look at SQLAlchemy. The object-relational-mapper (ORM) creates a 1:1 ma

Re: .title() - annoying mistake

Benjamin Schollnick wrote: > I’m sorry, but it’s as if he’s arguing for the sake of arguing. It’s > starting to feel very unproductive, and unnecessary. That was never five minutes just now! robert -- https://mail.python.org/mailman/listinfo/python-list

Re: .title() - annoying mistake

Chris Angelico wrote: > Cool thing is, nobody in Python needs to maintain anything here. That's great because I'm actually having trouble with sending log messages over the socket conection you helped me with, would you mind having a look? Regards, robert -- https://mail.python.org/mailman/listi

Re: How to set up a 'listening' Unix domain socket

> Chris Angelico wrote: [Helpful stuff] I'm actually trying to implement a SocketHandler for a Python logger. However, I can't get my handler on the client side to send anything. Do I need to subclass logging.SocketHandler and fill the various methods with meaning? The documentation doesn't say s

Re: .title() - annoying mistake

Karsten Hilbert wrote: > and life with that wart. Perfectly willing to as long as everybody agrees it's a wart ;-) robert -- https://mail.python.org/mailman/listinfo/python-list

Re: .title() - annoying mistake

Chris Angelico wrote: > There are a small number of characters which, when case folded, become > more than one character. The sharp S from German behaves thusly: > "ß".upper(), "ß".lower(), "ß".casefold(), "ß".title() > ('SS', 'ß', 'ss', 'Ss') Now we're getting somewhere. I'm a native German

Re: How to set up a 'listening' Unix domain socket

Chris Angelico wrote: > > Hmm, your formatting's messed up, but the code looks fine to me. (Be aware > that you seem to have a "selr" where it should be "self".) Didn't catch that because my program didn't even get to that point ;-) > >> However, when I try to send somthing to that socket, I get

Re: .title() - annoying mistake

Chris Angelico wrote: > If you still, after all these posts, have not yet understood that > title-casing *a single character* is a significant thing, I must admit I have no idea what title-casing even is, but I'm eager to learn. The documentation only talks about "words" and "first characters" and

How to set up a 'listening' Unix domain socket

Hello, I'm trying to set up a server that receives data on a Unix domain socket using the code below. import os from socketserver import UnixStreamServer, StreamRequestHandler SOCKET = '/tmp/test.socket' class Handler(StreamRequestHandler): def handle(self): data = selr.rfile.read() print(

Re: .title() - annoying mistake

Grant Edwards wrote: > On 2021-03-20, Robert Latest via Python-list wrote: >> Mats Wichmann wrote: >>> The problem is that there isn't a standard for title case, >> >> The problem is that we owe the very existence of the .title() method to too >> much we

Re: .title() - annoying mistake

Benjamin Schollnick wrote: > >> I agree with everything you say. Especially the open source part. But >> wouldn't you agree that .title() with all its arbitrary specificity to >> appear in the very core of a general purpose language is quite an oddity? > > No, because it book ends the issue. > > Up

Re: .title() - annoying mistake

Chris Angelico wrote: > On Sun, Mar 21, 2021 at 10:31 PM Robert Latest via Python-list > wrote: >> Yes, I get that. But the purpose it (improperly) serves only makes sense in >> the English language. > > Why? Do titles not exist in other languages? Does no other language &g

Re: .title() - annoying mistake

Benjamin Schollnick wrote: > > I’m sorry Robert, but just because it doesn’t meet your requirements, doesn’t > mean it’s useless. > > I use .title to normalize strings for data comparison, all the time. It’s a > perfect alternative to using .UPPER or .lower. > > Right in the documentation, it sp

Re: .title() - annoying mistake

Chris Angelico wrote: > On Sun, Mar 21, 2021 at 4:31 AM Robert Latest via Python-list > wrote: >> >> Mats Wichmann wrote: >> > The problem is that there isn't a standard for title case, >> >> The problem is that we owe the very existence of the .tit

Re: .title() - annoying mistake

Mats Wichmann wrote: > The problem is that there isn't a standard for title case, The problem is that we owe the very existence of the .title() method to too much weed being smoked during Python development. It makes specific assumptions about a specific use case of one specific language. It doesn

[SQLAlchemy] Struggling with association_proxy

I'm trying to implement a many-to-many relationship that associates Baskets with Items via an association object called Link which holds the quantity of each item. I've done that in SQLAlchemy in a very pedestrian way, such as when I want to have six eggs in a basket: 1. Find ID of Item with name

Re: A 35mm film camera represented in Python object

D.M. Procida wrote: > Hi everyone, I've created - > a representation of a Canonet G-III QL17 in Python. [...] > The Canonet G-III QL17 is one of my favourites. One of my reasons for > writing this code is to appreciate the intricate mechanical logic >

Re: How to implement logging for an imported module?

Richard Damon wrote: > On 3/8/21 4:16 AM, Robert Latest via Python-list wrote: >> Joseph L. Casale wrote: >>>> I couldn't find any information on how to implement logging in a library >>>> that doesn't know the name of the application that uses it. H

Re: Why assert is not a function?

Chris Angelico (and oters) wrote: [interesting stuff] I'm a late contributor here, but I'd just say: If you'd prefer a function for assert, just define a function that does what you want and be done with it. Much harder to do if assert() were a built-in function but you'd rather have a keyword ;-

Re: How to implement logging for an imported module?

Joseph L. Casale wrote: >> I couldn't find any information on how to implement logging in a library that >> doesn't know the name of the application that uses it. How is that done? > > That's not how it works, it is the opposite. You need to know the name of its > logger, and since you imported it,

How to implement logging for an imported module?

Hello, I'm trying to add logging to a module that gets imported by another module. But I only get it to work right if the imported module knows the name of the importing module. The example given in the "Logging Cookbook" also rely on this fact. https://docs.python.org/3/howto/logging-cookbook.ht

Re: Python2.7 unicode conundrum

Richard Damon wrote: > Why do you say it has been convert to 'Latin'. The string prints as > being Unicode. Internally Python doesn't store strings as UTF-8, but as > plain Unicode (UCS-2 or UCS-4 as needed), and code-point E4 is the > character you want. You're right, this wasn't the minimal exam

Python2.7 unicode conundrum

Hi folks, what semmingly started out as a weird database character encoding mix-up could be boiled down to a few lines of pure Python. The source-code below is real utf8 (as evidenced by the UTF code point 'c3 a4' in the third line of the hexdump). When just printed, the string "s" is displayed cor

Re: Package directory question

Ben Finney wrote: > Robert Latest via Python-list writes: > >> Because the main.py script needs to import the tables.py module from >> backend, I put this at the top if main.py: >> >>sys.path.append('../..') >>import jobwatch.backend.tables a

Package directory question

From: Robert Latest Hello, I'm building an application which consists of two largely distinct parts, a frontend and a backend. The directory layout is like this: |-- jobwatch | |-- backend | | |-- backend.py | | |-- __init__.py | | `-- tables.py | |-- fro

Package directory question

Hello, I'm building an application which consists of two largely distinct parts, a frontend and a backend. The directory layout is like this: |-- jobwatch | |-- backend | | |-- backend.py | | |-- __init__.py | | `-- tables.py | |-- frontend | | |-- __init__.py | | |-- main

Re: Weird side effect of default parameter

Steven D'Aprano wrote: > Python function default values use *early binding*: the default parameter > is evaluated, ONCE, when the function is defined, and that value is used > each time it is needed. Thanks, "early binding" was the clue I was missing. robert -- https://mail.python.org/mailman/

Weird side effect of default parameter

Hello, I don't understand the behavior of the code below. Why does the dict property "a" of both objects contain the same keys? This is only if "a=dict" is in the initializer. If I put self.a = dict() into the init function, I get two separate dicts class Foo(object): def __init__(self, x,

Why doesn't this method have access to its "self" argument?

Hi all, I'm still trying to find a simple way to implement a method (but not the full class) in C. Suggestions I have recived so far are good, but seem to be over the top for such a (seemingly) simple problem. I came up with the idea of implementing the class in Python, and just setting the method

Re: New syntax for blocks

r wrote: > Just thinking out loud here...what if variable assignments could > return a value... hmmm? Not to them selfs of course but to a caller, > like an if statement... > > if a=openfile: > # do something with a That's like in C. I sometimes miss it in Python. robert -- http://mail.python.

Re: New syntax for blocks

r wrote: > Forgive me if i don't properly explain the problem but i think the > following syntax would be quite beneficial to replace some redundant > "if's" in python code. > > if something_that_returns_value() as value: > #do something with value > > # Which can replace the following syntacti

Re: Python as network protocol

Grant Edwards wrote: > On 2009-11-10, Steven D'Aprano wrote: >>> How do you know for sure? Maybe the OP wants to use this thing >>> with 3 known researchers working on a cluster that is not even >>> visible to the outside world. > > And those three researchers are perfect? They've never even > ma

Re: Python tricks

RajNewbie wrote: > But, I still feel it would be much more aesthetically pleasing if I > can call a single procedure like > if infinite_loop() -> to do the same. You may find it aesthetically pleasing, and it may very well be, but it will obfuscate your code and make it less maintainable. robert

Re: Python tricks

RajNewbie wrote: >Is there a way - a python trick - to have a check such that if the > loop goes for more than x number of steps, it will cause an exception? > >I do understand that we can use the code like - >i = 0 >while True: > i++ > if i > 200: raise infinite_Loop_Exce

Memory debugging tool for Python/C API?

Hello, extending Python in C ist just the coolest thing since sliced bread (and I'm particularly happy because I really had started to miss C when I did more and more things in Python). I've got one question though. Tha C/API documentation is not quite clear (to me, anyway) on what happens exactl

[SOLVED] How can this script fail?

Dennis Lee Bieber wrote: >> On 2008-08-27 12:37, [EMAIL PROTECTED] wrote: >> > Got file in dir >> > Found in path: >> > >> > >> >> This looks strange... the same module in two dirs that only >> differ by case ? >> > Even stranger when you take into account that under Windows, path > name

Re: mktime overflow in March 2008?

Tim Roberts wrote: > What time zone are you in? March 30, 2008, was a Sunday. If that happened > to be the date your country transitioned to summer time, then the hour > between 2 AM and 3 AM would not exist. > > Does it work if you use 3:43 AM? Actually you're right; I'm in Middle Europe, and D

mktime overflow in March 2008?

Here's what happens on my Windows machine (Win XP / Cygwin) at work. I've googled a bit about this problem but only found references to instances where people referred to dates before the Epoch. Of course at home on my Linux box everything works. I know that everything has its limits somewhere, b

Re: Pointers/References in Python?

Gary Herron wrote: > No need. A Python list contains *references* to objects, not copies of > objects. (The same is true of variables, dictionaries, sets, and so > on...). Good to know. I just wanted to make sure before writing more code which in the end might not scale well. Thanks to all f

Re: Confounded by Python objects

satoru wrote: > As to "sample", it never get assigned to and when you say "append" the > class variable is changed in place. > hope my explaination helps. Sure does, thanks a lot. Here's an interesting side note: After fixing my "Channel" thingy the whole project behaved as expected. But there w

Re: Question on sort() key function

Peter Otten wrote: > Robert Latest wrote: > >> Paul Rubin wrote: >>> The attribute is on instances of File, not on the class itself. See >>> if this works: >>> >>>flist.sort(key=lambda f: f.mod_date.toordinal) >> >> It doesn't

Re: Question on sort() key function

Paul Rubin wrote: > The attribute is on instances of File, not on the class itself. See > if this works: > >flist.sort(key=lambda f: f.mod_date.toordinal) It doesn't throw an error any more, but neither does it sort the list. This, however, works: -- def by_date(f1, f2):

Question on sort() key function

Hello, I have this class: class File: def __init__(self): self.name = '' self.path = '' self.date = 0 self.mod_date = 0 self.keywords = [] self.url = '' ...and after creating a list of File o

Re: encrypting python modules

Steven D'Aprano wrote: > No, it's a serious question. You distribute Python code, and you're > worried that your users will modify the source code and then neglect to > mention it when they report bugs which they introduced. > > Before you build an elephant-proof fence around your house, it is q

Re: encrypting python modules

Paul Sijben wrote: >> >> You could check the MD5 hashes of your files. > > indeed but I still need to hook into import to do that reliably, right? Depends. In a job I once had I just supplied a shell script that spat out the MD5 sums of my sources. When I got a support request I had the customer

Re: encrypting python modules

Paul Sijben wrote: > The problem: I have a client-server app written in python. I want to > make sure that the client is not: > 1) destabilized by users accidentally or on purpose dropping python > files in the path (after which calling the helpdesk will not be useful) > 2) extended with "new feat

Re: "Canonical" way of deleting elements from lists

Sion Arrowsmith wrote: > Robert Latest <[EMAIL PROTECTED]> wrote: >> BTW, where can I find all methods of the built-in types? >>Section 3.6 only talks about strings and mentions the list append() method >>only in an example. Am I too stupid to read the manual, or is t

Re: How does unicode() work?

John Machin wrote: > When mixing unicode strings with byte strings, Python attempts to > decode the str object to unicode, not encode the unicode object to > str. Thanks for the explanation. Of course I didn't want to mix Unicode and Latin in one string, my snippet just tried to illustrate the p

Re: How does unicode() work?

Robert Latest wrote: > ...but it barfs when actually fed with iso8859-1 characters. Specifically, it says: UnicodeDecodeError: 'ascii' codec can't decode byte 0xf6 in position 0: ordinal not in range(128) which doesn't make sense to me, because I specifically asked for

How does unicode() work?

Here's a test snippet... import sys for k in sys.stdin: print '%s -> %s' % (k, k.decode('iso-8859-1')) ...but it barfs when actually fed with iso8859-1 characters. How is this done right? robert -- http://mail.python.org/mailman/listinfo/python-list

Re: "Canonical" way of deleting elements from lists

Hrvoje Niksic wrote: > keywords[:] = (s for s in keywords if s) Looks good but is so far beyond my own comprehension that I don't dare include it in my code ;-) robert -- http://mail.python.org/mailman/listinfo/python-list

Re: "Canonical" way of deleting elements from lists

Fredrik Lundh wrote: > keywords = filter(None, keywords) # get "true" items only Makes seinse. BTW, where can I find all methods of the built-in types? Section 3.6 only talks about strings and mentions the list append() method only in an example. Am I too stupid to read the manual, or is th

"Canonical" way of deleting elements from lists

Hello, >From a list of strings I want to delete all empty ones. This works: while '' in keywords: keywords.remove('') However, to a long-term C programmer this looks like an awkward way of accomplishing a simple goal, because the list will have to be re-evaluated in each iteration. Is ther

(SOLVED) Re: popen question

pexpect is the solution. Seems to wrap quite a bit of dirty pseudo-tty hacking. robert -- http://mail.python.org/mailman/listinfo/python-list

Re: popen question

Hrvoje Niksic wrote: > stdio uses different buffering strategies depending on the output > type. When the output is a TTY, line buffering is used; when the > output goes to a pipe or file, it is fully buffered. Makes sense. > If you see lines one by one, you are in luck, and you can fix things

Re: popen question

Marc 'BlackJack' Rintsch wrote: > Both processes have to make their communication ends unbuffered or line > buffered. Yeah, I figured something like that. > And do whatever is needed to output the numbers from ``slow`` > unbuffered or line buffered. Hm, "slow" of course is just a little test pr

popen question

Hello, look at this function: -- def test(): child = os.popen('./slow') for line in child: print line - The program "slow" just writes the numbers 0 through 9 on stdout, one line a second, and then quits. I would have expected the python program to spit

Re: Question about email-handling modules

Steven D'Aprano wrote: > message['to'] looks up the key 'to', raising an exception if it doesn't > exist. message.get('to') looks up the key and returns a default value if > it doesn't exist. Ah, so the [] notation got hung up on some message right at the beginning and didn't even let the scri

Question about email-handling modules

Hello, I'm new to Python but have lots of programming experience in C, C++ and Perl. Browsing through the docs, the email handling modules caught my eye because I'd always wanted to write a script to handle my huge, ancient, and partially corrupted email archives. Of course I know that this ki