python 函数

def 函数名(参数):
       
    ...
    函数体
    ...
    返回值

# ######### 定义函数 ######### 

# name 叫做函数func的形式参数，简称：形参
def func(name):
    print name

# ######### 执行函数 ######### 
#  ‘wupeiqi‘ 叫做函数func的实际参数，简称：实参
func(‘wupeiqi‘)

def func(name, age = 18):
    
    print "%s:%s" %(name,age)

# 指定参数
func(‘wupeiqi‘, 19)
# 使用默认参数
func(‘alex‘)

#注：默认参数需要放在参数列表最后

def t(x, *args):
    print(x)
    print(args)


t(1, ["a", 3])        # 列表变为元祖的一个元素               ===> 1 ([‘a‘, 3],)
t(1, *["a", 3])       # 遍历列表的变为元祖的一个个元素        ===> 1  (‘a‘, 3)

name = "liaobs"

def test():
    print("test", name)     ===>test liaobs

test()
print(name)         ===>liaobs

name = "liaobs"

def test():
    name = "sssbbbb"
    print("test", name)       ===>test sssbbbb

test()
print(name)          ===>liaobs

def test():
    global name                # global   指的是拿到的是全局的变量
    name = "sssbbbb"
    print("test", name)       ===>test sssbbbb

test()
print(name)        ===>sssbbbb

def test():
    name = "ssbb"
    def test2():
        global name
        name = "nimama"
    test2()
    print(name)      ===>xiaoa

print(name)     ===>ssbb
test()
print(name)    ===>nimama