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Python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

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 * 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))
[英文原文:The Evolution of a Python Programmer ]
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23 Responses to 程序员的进化

  1. 呵呵,我还是会最简单的啊

  2. zoujia says:

    译文的标题带上“Python”应该更准确一些吧\(^o^)/~不过看着这么多风格的程序,蛮有意思滴,O(∩_∩)O哈哈~

  3. ggd543 says:

    最终还是保留编程新手写的

  4. gcyy0106 says:

    编程新手用的是递归,其他都是循环,效率不一样的

  5. haitao says:

    不同层次的程序员编出的P【h】thon代码?

  6. Phoenix says:

    咱学Python也不止一年了, 依然还是新手型…汗.

  7. pf_miles says:

    不太明白这个区别,我觉得上述代码所谓“新手“和“懒惰的python程序员”写得可读性最好;
    效率上,“SICP”那个函数式的尾递归应该效率最好;
    读过SICP就懂尾递归?那可不一定,应该说这段代码是个函数式fan写的;

  8. andersonh says:

    写了两年半,水平依然停留在一年的水平,不过我的确学过C(额,虽然是上学学了语法而已)

  9. zhangshine says:

    python怎么写成Phthon了?第一段第二行

  10. 刘跃 says:

    没学过Python 机器上刚好有 就跑了下
    print factorial(6)语法错误,
    应该为print (factorial(6))

  11. xwsoul says:

    很早就看过的文章了 XD
    企业级程序员伤不起啊…

  12. huansinho says:

    我觉得亮点是企业级程序员

  13. 毕达哥拉斯半圆 says:

    哈哈,有点意思

  14. zouzou says:

    看到大英帝国程序员的import,我笑了:D

  15. Adam says:

    个人认为编程新手和专家级程序员2种比较容易理解

  16. wondery says:

    多余的括号也算SICP那个的亮点吧

  17. 李令 对这篇文章的反应是俺的神呀
  18. 文经小黑 对这篇文章的反应是
  19. 爱吃糖葫芦 对这篇文章的反应是飘过~
  20. 呵呵 对这篇文章的反应是
  21. Lilian 对这篇文章的反应是

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