Learn Python 2 or 3 first?

[Quantum Potatoid]

Hey, would anyone have any suggestions as to whether I should learn Python 2, or Python 3? In the long run I'll probably have to learn both.
While Python 2 has all the libraries and support, I'm thinking that getting a head start on Python 3, since it's the next up would give me an advantage in the long run.
Any thoughts?

[Ben-oni]

Can't answer that unless we know: Why Python?

[freeTheInfo]

Python 3 and the latest versions of Python 2 are mostly the same. Where they differ can cause quite a bit of frustration to you, however.

Can't answer that unless we know: Why Python?

This is somewhat true. If you need to use Python today for work or school: learn Python 2.7; you will need to support/troubleshoot many, many Python 2 programs while working for any company that uses Python. Many enviroments don't support Python 3 yet, so you'll be developing in Python 2.7 (or lower) anyways.

I would just learn Python 2. Python 3 isn't that much different, it's documentation is less mature, and when everyone does eventually switch over to Python 3 you won't be the only person with a few problems. The Python 2 to 3 tool fixes most minor stuff anyways, and leaves you with a few nasty suprises to troubleshoot, but any problem has almost certainly been solved on StackOverflow.

Gah, I was so confused the very first time I was running Python3 and

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print foo

didn't work. You have to use

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print(foo)

now.

[pedros]

in the later versions of python 2 you can always do something along these lines

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pete@pete-desktop:~/Desktop$ python
Python 2.7.2+ (default, Oct  4 2011, 20:03:08)
[GCC 4.6.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from __future__ import print_function
>>> from __future__ import division
>>> print(3/2)
1.5
>>>


rather than

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>>> print 3/2
1
>>>


[EvanED]

I just wish there was an from __future__ import different_types_arent_ordered_dammit so you could could properly get

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>>> 1 < "good"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unorderable types: int() < str()

instead of

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>>> 1 < "bad"
True

(What can I say? I like strong types. Same thing happens with something like 1 < []. I am disappointed that 1 < True continues to not produce an error even in Python 3 though.)

FWIW, I can tell you what I'm doing. For short scripts, I'm trying to use Python 3 more; I do really prefer Python 3. For longer programs, or where I'm more interested in portability, I stick with 2. So you pretty much hit the nail on the head in the first post: Python 3 is better and in a few years will be the norm, but there's a lot of inertia getting there.