函数参数，作用域

def foo(x,y,*args,a=1,b,**kwargs):
    print(x,y)
    print(args)
    print(a)
    print(b)
    print(kwargs)
foo(1,2,3,4,5,b=8,c=4,d=5)

1 2
(3, 4, 5)
1
8
{'c': 4, 'd': 5}

*后定义的参数，必须被传值（有默认值的除外），且必须按照关键字实参的形式传递

x=1
def f1():
    x=5        #f1的局部
    def f2():
        # x=4  #f2的局部
        print(x)
        print(locals())
    return f2         #返回函数名，地址
x=100
def f3(func):
    x=2       #f3的局部
    func()


x=1000    #全局
f3(f1())
print(globals())

5
{'x': 5}
{'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external.SourceFileLoader object at 0x0043C390>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, '__file__': 'F:/back01/hansu.py', '__cached__': None, 'x': 1000, 'f1': <function f1 at 0x003FB660>, 'f3': <function f3 at 0x021652B8>}

max=1
def f1():
    max=2
    def f2():
        # max=3
        def f3():
            # global max      #max=1  等于修改全局变量
            nonlocal max      #max=2   等于修改局部变量
            max=max+4
            print(max)
        f3()
    f2()

f1()
print(max)

6
1

def scope_test():

    def do_local():

        spam = "local spam" #此函数定义了另外的一个spam字符串变量，并且生命周期只在此函数内。此处的spam和外层的spam是两个变量，如果写出spam = spam + “local spam” 会报错

如果内部函数有引用外部函数的同名变量或者全局变量,并且对这个变量有修改.那么python会认为它是一个局部变量,又因为函数中没有gcount的定义和赋值，所以报错。

    def do_nonlocal():

        nonlocal  spam        #使用外层的spam变量

        spam = "nonlocal spam"

    def do_global():

        global spam

        spam = "global spam"

    spam = "test spam"

    do_local()

    print("After local assignmane:", spam)

    do_nonlocal()

    print("After nonlocal assignment:",spam)

    do_global()

    print("After global assignment:",spam)

 

scope_test()

print("In global scope:",spam)

　　输出是：

After local assignmane: test spam
After nonlocal assignment: nonlocal spam
After global assignment: nonlocal spam
In global scope: global spam