利用function修改nonlocal變數,利用function修改global變數

#用function修改global var的技巧
def ex5():
    var = 'foo'
    def inner():
        global var
        var = 'bar'
        print ('inside inner, var is ', var)
    inner()
    print ('inside outer function, var is ', var)


ex5()
print ("In global view, var is :",var)




執行結果:-----------------------------------------


inside inner, var is  bar
inside outer function, var is  foo
In global view, var is : bar






#用function修改nonlocal var的技巧
def ex5():
    var = 'foo'
    def inner():
        global var
        var = 'bar'
        print ('inside inner, var is ', var)
    inner()
    print ('inside outer function, var is ', var)


ex5()
print ("In global view, var is :",var)




執行結果:-----------------

inside inner, var is  bar
inside outer function, var is bar #由此行可知outer function中的值被修改為bar
Traceback (most recent call last):
  File "C:/Python32/setOuter.py", line 13, in <module>
    print ("In global view, var is :",var)
NameError: name 'var' is not defined