一个Python程序员的进化

http://developer.51cto.com/art/201102/244479.htm

 

http://www.pythonclub.org/hacks/evolution

 

 

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:
          result result  = result * i
          i i  = 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 ))