一个Python软件工程师的进化

不久前，在互联网上出现了一篇有趣的文章，讲的是对于同一个问题，不同层次的Python程序员编出的Python代码显示出了不同的风格，代码都很简单，有趣。下面让我们一起来看看一个Python程序员是进阶的全过程。

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不久前，在互联网上出现了一篇有趣的文章，讲的是对于同一个问题，不同层次的Python程序员编出的Python代码显示出了不同的风格，代码都很简单，有趣。

编程新手

def?factorial(x): ?
????if?x?==?0: ?
????????return?1 ?
????else: ?
????????return?x?*?factorial(x?-?1) ?
print?factorial(6)?

一年编程经验(学Pascal的)

def?factorial(x): ?
????result?=?1?
????i?=?2?
????while?i?<=?x: ?
????????resultresult?=?result?*?i ?
????????ii?=?i?+?1 ?
????return?result ?
print?factorial(6)?

一年编程经验(学C的)

def?fact(x):?#{ ?
????result?=?i?=?1; ?
????while?(i?<=?x):?#{ ?
????????result?*=?i; ?
????????i?+=?1; ?
????#} ?
????return?result; ?
#} ?
print(fact(6))?

一年编程经验(读过 SICP)

@tailcall ?
def?fact(x,?acc=1): ?
????if?(x?>?1):?return?(fact((x?-?1),?(acc?*?x))) ?
????else:???????return?acc ?
print(fact(6))?

一年编程经验(Python)

def?Factorial(x): ?
????res?=?1?
????for?i?in?xrange(2,?x?+?1): ?
????????res?*=?i ?
????return?res ?
print?Factorial(6)?

懒惰的Python程序员

def?fact(x): ?
????return?x?>?1?and?x?*?fact(x?-?1)?or?1 ?
print?fact(6)?

更懒的Python程序员

f?=?lambda?x:?x?and?x?*?f(x?-?1)?or?1 ?
print?f(6)?

Python 专家

fact?=?lambda?x:?reduce(int.__mul__,?xrange(2,?x?+?1),?1) ?
print?fact(6)?

Python 黑客

import?sys ?
@tailcall?
def?fact(x,?acc=1): ?
????if?x:?return?fact(x.__sub__(1),?acc.__mul__(x)) ?
????return?acc ?
sys.stdout.write(str(fact(6))?+?'\n')?

专家级程序员

from?c_math?import?fact ?
print?fact(6)?

大英帝国程序员

from?c_maths?import?fact ?
print?fact(6)?

Web 设计人员

def?factorial(x): ?
????#------------------------------------------------- ?
????#---?Code?snippet?from?The?Math?Vault??????????--- ?
????#---?Calculate?factorial?(C)?Arthur?Smith?1999?--- ?
????#------------------------------------------------- ?
????result?=?str(1) ?
????i?=?1?#Thanks?Adam ?
????while?i?<=?x: ?
????????#result?=?result?*?i??#It's?faster?to?use?*= ?
????????#result?=?str(result?*?result?+?i) ?
???????????#result?=?int(result?*=?i)?#?????? ?
????????result?=?str(int(result)?*?i) ?
????????#result?=?int(str(result)?*?i) ?
????????i?=?i?+?1?
????return?result ?
print?factorial(6)?

Unix 程序员

import?os ?
def?fact(x): ?
????os.system('factorial?'?+?str(x)) ?
fact(6)?

Windows 程序员

NULL?=?None?
def?CalculateAndPrintFactorialEx(dwNumber, ?
?????????????????????????????????hOutputDevice, ?
?????????????????????????????????lpLparam, ?
?????????????????????????????????lpWparam, ?
?????????????????????????????????lpsscSecurity, ?
?????????????????????????????????*dwReserved): ?
????if?lpsscSecurity?!=?NULL: ?
????????return?NULL?#Not?implemented ?
????dwResult?=?dwCounter?=?1?
????while?dwCounter?<=?dwNumber: ?
????????dwResult?*=?dwCounter ?
????????dwCounter?+=?1?
????hOutputDevice.write(str(dwResult)) ?
????hOutputDevice.write('\n') ?
????return?1?
import?sys ?
CalculateAndPrintFactorialEx(6,?sys.stdout,?NULL,?NULL,?NULL, ?
?NULL,?NULL,?NULL,?NULL,?NULL,?NULL,?NULL,?NULL)?

企业级程序员

def?new(cls,?*args,?**kwargs): ?
????return?cls(*args,?**kwargs) ?
? ?
class?Number(object): ?
????pass?
? ?
class?IntegralNumber(int,?Number): ?
????def?toInt(self): ?
????????return?new?(int,?self) ?
? ?
class?InternalBase(object): ?
????def?__init__(self,?base): ?
????????self.base?=?base.toInt() ?
? ?
????def?getBase(self): ?
????????return?new?(IntegralNumber,?self.base) ?
? ?
class?MathematicsSystem(object): ?
????def?__init__(self,?ibase): ?
????????Abstract ?
? ?
????@classmethod?
????def?getInstance(cls,?ibase): ?
????????try: ?
????????????cls.__instance ?
????????except?AttributeError: ?
????????????cls.__instance?=?new?(cls,?ibase) ?
????????return?cls.__instance ?
? ?
class?StandardMathematicsSystem(MathematicsSystem): ?
????def?__init__(self,?ibase): ?
????????if?ibase.getBase()?!=?new?(IntegralNumber,?2): ?
????????????raise?NotImplementedError ?
????????self.base?=?ibase.getBase() ?
? ?
????def?calculateFactorial(self,?target): ?
????????result?=?new?(IntegralNumber,?1) ?
????????i?=?new?(IntegralNumber,?2) ?
????????while?i?<=?target: ?
????????????result?=?result?*?i ?
????????????i?=?i?+?new?(IntegralNumber,?1) ?
????????return?result ?
? ?
print?StandardMathematicsSystem.getInstance(new?(InternalBase, ?
new?(IntegralNumber,?2))).calculateFactorial(new?(IntegralNumber,?6))?

Python 专家

fact?=?lambda?x:?reduce(int.__mul__,?xrange(2,?x?+?1),?1) ?
print?fact(6)?