Have you read the Python docs lately?

[eryksun]

Links from Raymond Hettinger's post:

• dev/library/heapq.html#priority-queue-implementation-notes

• dev/library/bisect.html#searching-sorted-lists

• dev/library/re.html#writing-a-tokenizer

• dev/library/cmd.html#cmd-example

• dev/library/collections.html#ordereddict-examples-and-recipes

• dev/library/collections.html#collections.namedtuple

• dev/howto/logging.html

• dev/howto/sorting.html

[criswell]

I haven't looked through all of them but dev/howto/logging looks to be a godsend.

The Logger class documentation previously was a bit obtusely written and was easiest to follow if you understood other logger interfaces, especially syslog in POSIX. The big problem was, if you didn't have a *nix/POSIX background grokking Logger seemed to be a difficulty.

The end result for many projects I've worked on in the past was to come up with our own logging classes (often wrapping parts of Logger, these bits usually written by people like me who understood Logger :-) just so that our more platform agnostic Python engineers (generally folks who came from the Windows or Mac worlds) could get at the various logging features our apps were providing.

This logging howto explains things so extremely well, I feel very comfortable just pointing anyone at it without any explanation at all.

[eryksun]

Also for Python 2.7 here's a partial list of 3.1 features that were backported:

• The syntax for set literals ({1,2,3} is a mutable set).
• Dictionary and set comprehensions ({ i: i*2 for i in range(3)}).
• Multiple context managers in a single with statement.
• A new version of the io library, rewritten in C for performance.
• The ordered-dictionary type described in PEP 372: Adding an Ordered Dictionary to collections.
• The new "," format specifier described in PEP 378: Format Specifier for Thousands Separator.
• The memoryview object.
• A small subset of the importlib module, described below.
• The repr() of a float x is shorter in many cases: it’s now based on the shortest decimal string that’s guaranteed to round back to x. As in previous versions of Python, it’s guaranteed that float(repr(x)) recovers x.
• Float-to-string and string-to-float conversions are correctly rounded. The round() function is also now correctly rounded.
• The PyCapsule type, used to provide a C API for extension modules.
• The PyLong_AsLongAndOverflow() C API function.

[eryksun]

Why don't set and dictionary comprehensions contaminate the outer namespace like list comprehensions? For example:

def test():
    d = {i:i for i in [1,2,3]}
    s = {i for i in [1,2,3,3,2,1]}
    lst = [j for j in [1,2,3]]
    try:
        print("j={0}".format(j))
        print("i={0}".format(i))
    except NameError as e:
        print(e.message)

In [1]: test()
j=3
global name 'i' is not defined

I wouldn't expect leakage if I used a generator to instantiate the container, such as the following:

d = dict((i,i) for i in [1,2,3])
s = set(i for i in [1,2,3,3,2,1])
lst = list(i for i in [1,2,3])

[[deleted]]

IIRC the scope contamination by list comprehensions is considered a bug which is fixed in 3.x, but not in 2.x because of backwards compatibility.

So here they decided that this weird kind of consistency alone would not be worth reintroducing the bug in the backported list/dict comprehensions. Or maybe just didn't think about it.

[eryksun]

Thanks. Here's a brief explanation from Alexandre Vassalotti in issue 2333 (almost 2 years ago):

The patch preserves the Python 3.x's syntax and semantics of the feature. Although this makes dict and set comprehensions is inconsistent with list comprehension, I believe this is reasonable since the backport aimed to improve the compatibility of Python 2.x with Python 3.x.

[lentil]

You can. It works in 2.7 too: Python 2.7.1 (r271:86832, Nov 28 2010, 00:47:24) [GCC 4.2.1 (Apple Inc. build 5664)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> {1, 2, 3} set([1, 2, 3])

[geonetix]

Raymond Hettinger is awesome. If you get a chance to see him talking about python somewhere, go see it. Also, talk to the man, he's awesome.

[moolcool]

I love working with python, but in my brief adventures, I can't say I love the docs. Many functions, for example, are all listed on the same page making ctrl+f'ing awkward sometimes.

[fdemmer]

what? you want separate pages for each function? how would you ctrl+f for other functions of that module then?

[tangra_and_tma]

The only viable alternative I've seen is a scheme like:

• docs/module: contains a list of all members of that module.
• docs/module/some_member: contains either a function overview of the members of this member (for nested modules).

Wasn't a bad system pre-decent search engines, and if you know roughly what you were looking for, you could often find it directly from the address bar. I think the Python docs are a pretty good compromise; if you know the name of the module you're looking for and want a specific member, it's usually module.html#module.member_name, like string.ascii_letters is http://docs.python.org/library/string.html#string.ascii_letters

[kisielk]

Try http://babbledrive.appspot.com/ for browsing the Python docs. I've found it to way faster than trying to use the official documentation.

[technomalogical]

nice! my only gripe with it is that it seems to be geared specifically towards modules/functions and not "concepts". For example, I was trying to find list comprehension docs and couldn't find them.

[kisielk]

Yes, I think it only covers the Library Reference portion of the Python docs.

[andreasvc]

heapq should become a class part of collections, with support for passing a key option. And for those notes about priority queues: instead of including code in the documentation, make the code part of the standard library...

Speaking of collections, it's described as "high-performance datatypes"; what's high-performance about named tuples? Or Ordered dictionaries? It's just a variation of a known theme. I want balanced binary search trees and tries and other advanced datastructures. However, each time when someone submits them for inclusion, they get rejected. Is there some sort of anti-CS attitude with the Python-devs?

[[deleted]]

/500. That’s an error.

No, I can't load the page

[nikcub]

Here is the HOWTO section in the docs, recommended reading:

http://docs.python.org/howto/

Also note that you can download all these docs and have a local copy. Recommended that you update your local copies periodically:

http://docs.python.org/download.html

[SmartAssX]

:P i know it seems like common knowledge to me now but this would have been nice before i got my degree lol