一个Python程序员的进化
编程新手
def factorial(x): if x == 0: return 1 else: return x * factorial(x - 1) //递归!不简单啊! 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; //连续赋值! 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))) //递归! 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): //工具! 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 //语法! print fact(6)
更懒的Python程序员
f = lambda x: x and x * f(x - 1) or 1 //匿名函数+语法! print f(6)
Python 专家
fact = lambda x: reduce(int.__mul__, xrange(2, x + 1), 1) //匿名函数+工具+底层! print fact(6)
Python 黑客
import sys @tailcall def fact(x, acc=1): if x: return fact(x.__sub__(1), acc.__mul__(x)) //直接用底层!别人看不懂! return acc sys.stdout.write(str(fact(6)) + '\n')
专家级程序员
from c_math import fact //用标准库! 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) //不断优化! #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)) //代码量少! 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, //自个都晕! 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)) //面向对象!