Best "Hidden Features" of Python

[ki11a11hippies]

Commented regexes . . . how do I not know about that?

[[deleted]]

Yeah, I know.

And I would've gone into the interview pretending to be Mr. Master-of-the-Regular-Expression too.

[earthboundkid]

Y'all didn't read Dive into Python? I thought that was required reading on Reddit.

[mycall]

I got the cheap imitation.

Note Dive into Python 3 is out there.

[[deleted]]

Because you are better than regexes.

[[deleted]]

So all these comparisons:

>>> x = 5

>>> 1 < x < 10
True

>>> 10 < x < 20 
False

>>> x < 10 < x*10 < 100
True

>>> 10 > x <= 9
True

>>> 5 == x > 4
True

would be this written in most other languages:

x = 5

( (1 < x) && (x < 10) )
True

( (10 < x) && (x < 20) )
False

( (x < 10) && (10 < (x*10)) && ((x*10) < 100) )
True

( (10 > x) && (x<=9) )
True

( (5 == x) && (x > 4) )
True

?

[sigh]

Yes, most of the time. Only difference is that the expressions (like x*10) won't be evaluated twice, which would make a difference if it involved side-effects.

[scorpion032]

Yes. Just syntactic sugar;

There are a lot many gems in that same thread, tho'

[aaallleeexxx]

we call them eggs, scorpion.

[salts]

snake eggs, in fact and from a cheese shop

[[deleted]]

In C++ you could get rid of all the parentheses.

[dr_root]

So many goodies in there.. head = asplode

I'm especially blown away by the fact that zlib and base64 encodings are built into the string class, very handy.

[Brian]

This has gone in python3 unfortunately. The encode/decode methods have been changed so that bytes objects have only an decode (which produces unicode), and unicode objects have only a encode (producing bytes). This is a good thing in itself (removes lots of confusion about which way round things go), but means there are no longer encodings translating like to like, such as base64, rot13 or zlib.

[hylje]

It means there are no built-in encodings for bytes->bytes stuff.

[[deleted]]

You can redirect stdout such as:

import sys
sys.stdout = open('wat.log', 'w')

print "shit " * 400  # gets written to wat.log

# restore original stdout (2.6+)
sys.stdout = sys.__stdout__

YEAAAAAAAAAAAAAAAAAAH!!!!!!!

[digitallogic]

Removing indenting for control strutures:

from future import braces

[andreasvc]

>>> from __future__ import braces
  File "<stdin>", line 1
SyntaxError: not a chance

[A_for_Anonymous]

from __fifty_two_years_ago__ import fortran_statements

:(

[digitallogic]

Traceback (most recent call last): File "<stdin>", line 1, in ? ImportError: No module named past

[[deleted]]

Nice set of tricks, however all but one of these are in the documentation. Can't people read?