【外刊IT评论】Python 程序员的进化

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，不同层次的程序员编出的Phthon代码显示出了不同的风格，代码都很简单，有趣。这篇文章的原始出处在这里，我把它整理了一下，并修改了几处错误。

编程新手

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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)

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

一年编程经验(学C的)

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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)

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@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)

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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

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

更懒的Python程序员

1 2	f = lambda x: x and x * f(x - 1) or 1 print f(6)

Python 专家

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

Python 黑客

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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

1 2	from c_math import fact print fact(6)

大英帝国程序员

1 2	from c_maths import fact print fact(6)

Web 设计人员

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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

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

Windows 程序员

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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

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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))