hacks:evolution

# The Evolution of a Python Programmer

A while back, clever snippets of code portraying how different people programming in Python went about solving the same problem, appeared on the internet. Needless to say, it was pretty funny and despite its popularity, not many people seem to know of it when I bring it up. Being as lazy as I am when it comes to these sorts of things, I am blogging about it now. Almost three years later. It has been posted and reposted dozens of times, but full of geek pride, I can proudly say that I helped create it by correcting some of the mistakes in the original. How’s that for major geek cred?

## Newbie Programmer

```def factorial(x):
if x == 0:
return 1
else:
return x * factorial(x - 1)
print factorial(6)```

## First Year Programmer (Studied Pascal)

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

## First Year Programmer (Studied C)

```def fact(x): #{
result = i = 1;
while (i <= x): #{
result *= i;
i += 1;
#}
return result;
#}
print(fact(6))```

## First Year Programmer (Read SICP)

```@tailcall
def fact(x, acc=1):
if (x > 1): return (fact((x - 1), (acc * x)))
else:       return acc
print(fact(6))```

## First Year Programmer (Python)

```def Factorial(x):
res = 1
for i in xrange(2, x + 1):
res *= i
return res
print Factorial(6)```

## Lazy Python Programmer

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

## Lazier Python Programmer

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

## Python Expert Programmer

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

## Python Hacker

```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')```

## EXPERT PROGRAMMER

```from c_math import fact
print fact(6)```

## BRITISH EXPERT PROGRAMMER

```from c_maths import fact
print fact(6)```

## Web Designer

```def factorial(x):
#-------------------------------------------------
#--- Code snippet from The Math Vault          ---
#--- Calculate factorial (C) Arthur Smith 1999 ---
#-------------------------------------------------
result = str(1)
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 Programmer

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

## Windows Programmer

```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)```

## Enterprise Programmer

```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))```

## 参考

hacks/evolution.txt · 最后更改: 2011/01/24 06:30 (外部编辑)

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