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简介
import this
Python 之禅的来源
The Anti-Zen of Python

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本篇博文基本没有技术含量，对 Python 之禅有兴趣的，可以扫一下。

简介

Python 之禅： import this

In [1]: import this
The Zen of Python, by Tim Peters

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!

网上有各种翻译版本，啄木鸟社区的 Zen of Python -- 蟒之禅！作了一个汇总。

官方也将之编入了 PEP 20 。

import this

s = """Gur Mra bs Clguba, ol Gvz Crgref

Ornhgvshy vf orggre guna htyl.
Rkcyvpvg vf orggre guna vzcyvpvg.
Fvzcyr vf orggre guna pbzcyrk.
Pbzcyrk vf orggre guna pbzcyvpngrq.
Syng vf orggre guna arfgrq.
Fcnefr vf orggre guna qrafr.
Ernqnovyvgl pbhagf.
Fcrpvny pnfrf nera'g fcrpvny rabhtu gb oernx gur ehyrf.
Nygubhtu cenpgvpnyvgl orngf chevgl.
Reebef fubhyq arire cnff fvyragyl.
Hayrff rkcyvpvgyl fvyraprq.
Va gur snpr bs nzovthvgl, ershfr gur grzcgngvba gb thrff.
Gurer fubhyq or bar-- naq cersrenoyl bayl bar --boivbhf jnl gb qb vg.
Nygubhtu gung jnl znl abg or boivbhf ng svefg hayrff lbh'er Qhgpu.
Abj vf orggre guna arire.
Nygubhtu arire vf bsgra orggre guna *evtug* abj.
Vs gur vzcyrzragngvba vf uneq gb rkcynva, vg'f n onq vqrn.
Vs gur vzcyrzragngvba vf rnfl gb rkcynva, vg znl or n tbbq vqrn.
Anzrfcnprf ner bar ubaxvat terng vqrn -- yrg'f qb zber bs gubfr!"""

d = {}
for c in (65, 97):
    for i in range(26):
        d[chr(i+c)] = chr((i+13) % 26 + c)

print("".join([d.get(c, c) for c in s]))

看了上面的源代码，发现该模块不是直接输出 Python 之禅的内容，而是经过了一层加密（rot13）。

其实 Python 的 decode 方法本身就支持 rot13。

In [8]: import string

In [9]: string.letters
Out[9]: 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'

In [10]: string.letters.decode("rot13")
Out[10]: u'nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM'

对于为什么会有这种蛋疼的实现，网上也人有发出了同样的疑问 this.py too verbose 。

该帖子里面的一句话作了明确的解释：

Sorry, Guido deliberately refused to use rot13.  He wants
it to be obscure.  I told him that I instantly recognized
the by-hand implementation of rot13, but had no idea
what .decode('rot13') might do.  He wasn't swayed <wink>.

如果想深入了解 rot13, 请参见 wiki: rot13 。

Python 之禅的来源

import this and The Zen of Python 这个帖子里面，比较详细得讲述了 Python 之禅的历史。有兴趣的可以看一下。

The Anti-Zen of Python

PYPI 上面有人恶搞了个 that 库。

可通过以下命令安装：

1	$ pip install that

import that 输出的内容的意思和 Python 之禅恰好相反，叫做反 Python 之禅，哈哈。

In [1]: import that
The Anti-Zen of Python, by Daniel Greenfeld

Ugly is better than beautiful.
Implicit is better than explicit.
Complicated is better than complex.
Complex is better than simple.
Nested is better than flat.
Dense is better than sparse.
Line code counts.
Special cases are special enough to break the rules.
Although purity beats practicality.
Errors should always pass silently.
Spelchek iz fur loosers.
In the face of ambiguity, one guess is as good as another.
There should be many ways to do it.
Because only a tiny minority of us are Dutch.
Get things running, then fix them later.
If the implementation is hard to explain, it's enterprisey.
If the implementation is easy to explain, it won't take enough time to do.
Namespaces are too hard, just use "from module import *"!

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this标准库源码学习

简介

import this

Python 之禅的来源

The Anti-Zen of Python

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