趣文：Python程序员的进化史+python电子书资料分享！
下面代码来自 fmeyer ，列举了各种程序员所写的阶乘算法代码，甚至包括网页设计师的。
001
#新手程序员002
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def factorial (x):004
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if x == 0:006
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return 1008
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else:010
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return x * factorial (x - 1)012
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print factorial (6)014
015
#有一年 Pascal 经验的程序员016
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def factorial (x):018
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result = 1020
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i = 2022
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while i <= x:024
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result = result * i026
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i = i + 1028
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return result030
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print factorial (6)032
033
#有一年 C 经验的程序员034
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def fact (x): #{036
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result = i = 1;038
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while (i <= x): #{040
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result *= i;042
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i += 1;044
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#}046
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return result;048
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#}050
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print(fact (6))052
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#有一年 SICP 经验的程序员054
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@tailcall056
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def fact (x， acc=1):058
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if (x > 1): return (fact ((x - 1)， (acc * x)))060
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else: return acc062
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print(fact (6))064
065
#有一年 Python 经验的程序员066
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def Factorial (x):068
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res = 1070
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for i in xrange (2, x + 1):072
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res *= i074
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return res076
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print Factorial (6)078
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#懒惰的 Python 程序员080
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def fact (x):082
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return x > 1 and x * fact (x - 1) or 1084
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print fact (6)086
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#更懒惰的 Python 程序员088
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f = lambda x: x and x * f (x - 1) or 1090
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print f (6)092
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#专家级 Python 程序员094
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import operator as op096
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import functional as f098
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fact = lambda x: f.foldl (op.mul, 1, xrange (2, x + 1))100
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print fact (6)102
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#Python 黑客104
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import sys106
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@tailcall108
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def fact (x， acc=1):110
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if x: return fact (x.__sub__(1)， acc.__mul__(x))112
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return acc114
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sys.stdout.write (str (fact (6)) + '')116
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#专家级程序员118
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import c_math120
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fact = c_math.fact122
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print fact (6)124
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#英国专家级程序员 （译注：在英式英语中，“数学”的简写，多用“maths”，不是“math"。）126
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import c_maths128
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fact = c_maths.fact130
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print fact (6)132
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#网页设计师134
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def factorial (x):136
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#-------------------------------------------------138
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#--- 这段代码是从 Math Vault 那弄过来滴---140
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#--- 计算阶乘 （C）亚瑟·史密斯 1999 年---142
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#-------------------------------------------------144
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result = str (1)146
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i = 1 #谢谢亚当148
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while i <= x:150
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#result = result * i #It's faster to use *=152
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#result = str (result * result + i)154
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#result = int (result *= i) #??????156
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result str (int (result) * i)158
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#result = int (str (result) * i)160
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i = i + 1162
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return result164
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print factorial (6)166
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#Unix 程序员168
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import os170
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def fact (x):172
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os.system ('factorial ' + str (x))174
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fact (6)176
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#Windows 程序员178
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NULL = None180
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def CalculateAndPrintFactorialEx (dwNumber,182
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hOutputDevice,184
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lpLparam,186
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lpWparam,188
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lpsscSecurity,190
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*dwReserved):192
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if lpsscSecurity != NULL:194
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return NULL #Not implemented196
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dwResult = dwCounter = 1198
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while dwCounter <= dwNumber:200
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dwResult *= dwCounter202
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dwCounter += 1204
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hOutputDevice.write (str (dwResult))206
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hOutputDevice.write ('')208
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return 1210
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import sys212
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CalculateAndPrintFactorialEx (6, sys.stdout, NULL, NULL, NULL, NULL, NULL,214
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL)215
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#企业程序员217
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def new (cls, *args, **kwargs):219
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return cls (*args, **kwargs)221
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class Number (object):223
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pass225
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class IntegralNumber (int, Number):227
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def toInt (self):229
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return new (int, self)231
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class InternalBase (object):233
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def __init__(self, base):235
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self.base = base.toInt ()237
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def getBase (self):239
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return new (IntegralNumber, self.base)241
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class MathematicsSystem (object):243
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def __init__(self, ibase):245
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Abstract247
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@classmethod249
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def getInstance (cls, ibase):251
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try:253
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cls.__instance255
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except AttributeError:257
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cls.__instance = new (cls, ibase)259
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return cls.__instance261
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class StandardMathematicsSystem (MathematicsSystem):263
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def __init__(self, ibase):265
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if ibase.getBase () != new (IntegralNumber, 2):267
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raise NotImplementedError269
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self.base = ibase.getBase ()271
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def calculateFactorial (self, target):273
274
result = new (IntegralNumber, 1)275
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i = new (IntegralNumber, 2)277
278
while i <= target:279
280
result = result * i281
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i = i + new (IntegralNumber, 1)283
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return result285
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print StandardMathematicsSystem.getInstance (new (InternalBase,287
new (IntegralNumber, 2))) .calculateFactorial (new (IntegralNumber, 6))
下面代码是 kohashi 给出的，他说是在邮局看到的。
view source
?
01
#VBA 程序员02
03
def factorial (x):04
05
if x == 0:06
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return 108
09
if x == 1:10
11
return x12
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if x == 2:14
15
return x * (x-1)16
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if x == 3:18
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return x * (x-1) * (x-2)20
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if x == 4:22
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return x * (x-1) * (x-2) * (x-3)24
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if x == 5:26
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return x * (x-1) * (x-2) * (x-3) * (x-4)28
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if x == 6:30
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return x * (x-1) * (x-2) * (x-3) * (x-4) * (x-5)32
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print factorial (6)
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