Critique of Python 3

Consistency is an important quality property of a language. One of my main points of critic agains PHP was inconsistency (see PHP: A strange language). Let's see where Python is inconsistant.

Naming

Underscores or not

PEP 8 recommends underscores for functions, if I remember it correctly. However, some built-in functions do not follow this naming scheme:

float.fromhex
bytes.startswith
str.startswith
str.is_digit
os.path.isfile and probably all other os functions.

snake_case or camelCase

Where	Is	Should be
Logging module (everywhere)	logging.getLogger	logging.get_logger

Methods / Properties / Functions

len: Each container type should have a property length. One the one hand, this is done in many other languages. On the other hand, it indicates that getting the length is a constant-time operation.

Datetime

Have a look at the following code:

import datetime

x = datetime.datetime(2017, 01, 01, 12, 00)
y = datetime.datetime(2017, 01, 02, 12, 00)

print("Seconds elapsed: {}".format((y - x).seconds))

What would you expect the output to be? I expected 24 * 60 * 60. But it is 0. What you were looking for is (y - x).total_seconds.

Tutorial

A tutorial is a method of transferring knowledge and may be used as a part of a learning process. More interactive and specific than a book or a lecture; a tutorial seeks to teach by example and supply the information to complete a certain task.

Source: Wikipedia

Tutorials are very important for programming languages. Especially the ones which introduce the core concepts of a language. I think Python should have 3 tutorials:

How to install: Detailed instructions for all major systems. At the beginning, the user should be asked about his system (and get help how to find out which system he has) and then get only the instructions necessary for his system.
Programming beginners Python tutorial: Python is probably the first programming language some people use. And I think it is suited well for them. However, there should be an official Python tutorial for people who have to learn what a variable is and what functions are. This tutorial might contain information which over-simplifies stuff. wiki.python.org/moin/BeginnersGuide is similar to that, but it seems not to be very well structured.
Advanced programmers Python tutorial: For people who know the basic concepts of programming.

These three tutorials should be linked from python.org/tutorials.

Documentation

Every function / object / method should have examples. So the len function should additionally have this:

>>> some_list = [23, 12, -3, 0]
>>> len(some_list)
4
>>> other_list = [[12, 32, 456], [1, 2, 3]]
>>> len(other_list)
2

I think the PHP documentation is awesome. Take a look at strlen. It is immediately clear how to use it, which versions are supported, what types the parameters should have and what the return value is. Functions which you might have looked for can be found under "See Also" and some difficulties can be found under "User Contributed Notes". I have never seen a similar well-structured and written documentation of a programming language (not for Java, C, C++, Haskell, JavaScript)

Also, runtime information in big-O notation as well as space information would be nice.

PyPI

gi is for GTK, but the module https://pypi.python.org/pypi/gi "overrides" it. That should not be possible. So there is an issue with namespaces.

Joining lists

Joining a list of strings works like this in Python 3:

>>> a = [str(el) for el in range(5)]
>>> a.join(" ")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'list' object has no attribute 'join'
>>> " ".join(a)
'0 1 2 3 4'

However, I think it is much more logical to apply a join method of a list with a string argument than a join method of a string with a list argument. This might be the case because I know how join is done in JavaScript.

Module specific

Base64

The module base64 contains the functions b16decode, b16encode, b32decode, b32encode, b64decode, b64encode, decode, decodestring, encode, encodestring, standard_b64decode, standard_b64encode, urlsafe_b64decode, urlsafe_b64encode.

It is not good to have a module called base64 and give it base32decode. But that is probaly for historic reasons and I cannot think of a better name by now. text_encoding? That would have "encoding" in the name.

However, I think the module should only have the functions

str encode(str s, int base=64)
str decode(str s, int base=64, casefold)

I don't see a good reason why reading and writing should be done by this module.

Scipy - PIL

PIL uses (width, height) (e.g. in Image.new) and SciPy uses (height, width).