python一些常用小函数，不定时更新~

首字母大写(map函数)

#!/usr/bin/env python
# -*- coding: utf-8 -*-
def change(str):
    return {'a':'A','b':'B','c':'C','d':'D','e':'E','f':'F','g':'G','h':'H','i':'I','j':'J','k':'K','l':'L','m':'M','n':'N','o':'O','p':'P','r':'R','s':'S','t':'T','u':'U','v':'V','w':'W','x':'X','y':'Y','z':'Z'}[str]
def char(str):
    for i in str:
        return change(str[0])+str[1:]
arr1 = ['asdas','basd','zxczas']
print map(char,arr1)
#结果
['Asdas', 'Basd', 'Zxczas']

过滤奇偶数（filter函数

def is_odd(n):
    return n % 2 == 1
arr = range(20)
print filter(is_odd,arr)

#结果
C:\Python27\python.exe G:/Python/script.py
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]

删除空字符串（filter和strip函数）

#!/usr/bin/env python
# -*- coding: utf-8 -*-
def not_empty(s):
    return s and s.strip()

print filter(not_empty,['A','B','','D','E','','','asdasd',''])

#结果
#C:\Python27\python.exe G:/Python/script.py
#['A', 'B', 'D', 'E', 'asdasd']

判断一个数是否是素数

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import math
def isPrime(n):
    if n <= 1:
        return False
    for i in range(2, int(math.sqrt(n)) + 1):
        if n % i == 0:
            return False
    return True
print isPrime(127)

排序

#!/usr/bin/env python
# -*- coding: utf-8 -*-
def cmp_ignore_case(s1, s2):
    if s1 < s2:
        return -1
    if s1 > s2:
        return 1
    return 0
print sorted([213,22,321,52,223,12],cmp_ignore_case)

冒泡排序

#!/usr/bin/env python
# -*- coding: utf-8 -*-
def sort(nums):
    for i in range(len(nums)-1,-1,-1):
        for j in range(i):
            if nums[j] > nums[j+1]:
                nums[j],nums[j+1] = nums[j+1],nums[j]
    return nums
arr = [123,25,23,123,66,2323,125,66,22,66]
print range(len(arr)-1,-1,-1)
print sort(arr)

#测试
C:\Python27\python.exe G:/Python/script.py
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
[22, 23, 25, 66, 66, 66, 123, 123, 125, 2323]

类的定义 引用

#!/usr/bin/env python
# -*- coding: utf-8 -*-
class Studet(object):
    def __init__(self,name,score):
        self.name = name
        self.score = score
    def print_score(self):
        print ('%s:%s' % (self.name,self.score))

Studet('kou',100).print_score()

### 斐波那切数列

#!/usr/bin/env python
# -*- coding: utf-8 -*-

class Fib(object):
    def __init__(self):
        self.a,self.b = 0 , 1
    def __iter__(self):
        return self
    def next(self):
        self.a,self.b = self.b,self.a+self.b
        if self.a > 10000:
            raise StopIteration()
        return self.a
for n in Fib():
    print n

try 机制

try:
    print 'try...'
    r = 10 / 0
    print 'result',r
except ZeroDivisionError,e:
    print 'execpt:',e
finally:
    print 'finally...'
print 'END'

#jieguo
C:\Python27\python.exe G:/Python/hello.py
try...
execpt: integer division or modulo by zero
finally...
END