Python2.7 -- 如何使用函数

函数使用和创建入门

# coding:utf-8

def my_def():
return '你调用我想干啥！！！！！'

def my_pass():
pass

def my_return_more(x, y, z):
return x, y, z

print '官网的函数参考：http://docs.python.org/2/library/functions.html#abs'

print '函数的用法：%s ' % abs(-20)
print '数据类型转换：%s' % int('123')

print '调用我的时候，得先声明函数，要注意顺序，调用my_def：%s' % my_def()
print '什么都不想干 ：%s' % my_pass()
x1, y1, z1 = my_return_more(1, 2, 3)
print '返回多个值：%s %s %s'  % (x1, y1, z1)

千奇百怪的参数

# coding:utf-8

def my(x=2):
return x;

def my_more(a, x=2):
return a, x

def my_list(l=[]):
return l;

def my_charge(number):
result = 0
for i in number:
result += i
return result

def my_charge1(*number):
result = 0
for i in number:
result += i
return result

def person(name, age, **kw):
print 'name:', name, 'age:', age, 'other:', kw

print '函数默认的参数: %s' % my()
a1, x1 = my_more(1)
print '函数多个参数的: %s %s' % (a1, x1)

l = [1, 2, 3]
print '参数List，返回：%s' % my_list(l)

print '可变参数, 返回：%s' % my_charge([1, 1, 1, 1, 2])
print '可变参数, 返回：%s' % my_charge1(1, 1, 1, 1, 2)

print '**标识DICT参数类型：%s' % person('Bob', 35, city='Beijing')

其他特性

# coding:utf-8
L = ['Michael', 'Sarah', 'Tracy', 'Bob', 'Jack']

print '切片操作：', L[0:3]
print '切片操作：', L[:3]
print '切片操作：', L[1:3]

d = {'a': 1, 'b': 2, 'c': 3}
def diedai():
for value in d.itervalues():
print value

from collections import Iterable
def isCollections():
print 'd是否可以进行迭代', isinstance(d, Iterable)

print '迭代对象：', diedai()

isCollections()

list = range(1, 11)
print '生成List', list

函数作为返回值

# coding:utf-8
def lazy_sum(*args):
def sum():
ax = 0
for n in args:
ax = ax + n
return ax

return sum

s = lazy_sum(1, 2, 3, 4, 5)
print '函数作为返回值，执行函数：', s()