python 快速入门函数

def func():
print("hello world")
return "hello world"

a = func()
print(a)

# hello world
# hello world
def func_args(a, b, c):
print(a, b, c)

func_args(10, 20, "helloworld")

#10 20 helloworld

def func_args(a, b="a", c=10):
print(a, b, c)

func_args(10)
#10 a 10

def func_args(a, b, *args):
print(args)
print(len(args))

func_args(10, 20, 30, 30, 40, 60, 100)
#(30, 30, 40, 60, 100)
#5
def func_args(a, b, c):
print(a, b, c)
#10 30 20
func_args(a=10, c=20, b=30)

def func_args(a1=1, a2=2, a3=3, a4=4):
pass
func_args(a2=200, a4=400)

def func_args(**kwargs):
print(kwargs)
#{'a': 10, 'b': 20, 'c': 'hello', 'd': 'hello'}
func_args(a=10, b=20, c="hello", d="hello")

def func_args(*args, **kwargs):
print(args)
print(kwargs)

func_args(10, 20, a=10, b=20, c=30)
'''
(10, 20) //第一个会变成元祖
{'a': 10, 'b': 20, 'c': 30}//后面是字典
'''

var = 50
def func():
global var # ::
var =100 # 局部变量 只有函数里的才会是局部变量 加上上面那一句 下面输出100 否则50

func()
print(var)
#100

var=50
if True:
var=100 //不在函数里就是全局的
print(var)

#100