是否打印功能具有在python

Question

def func_print_x(): 
    ## x += 1 ## if uncomment this line, it will raise UnboundLocalError: local variable 'x' referenced before assignment 
    print x 
if __name__ = '__main__': 
    x = 4 
    func_print_x() 

更多 '特权' 在功能func_print_x（），有两个规则：

1. 为 '线X + = 1'，可变x被视为局部变量;
2. 当来到'打印x'时，变量x似乎是全局变量。

是否print函数有更多'特权'？

Answer 1

def f(): 
    global s 
    print s 
    s = "That's clear." 
    print s 


s = "Python is great!" 
f() 
print s 

O/P

Python is great! 
That's clear. 
That's clear. 

但whne你没有global

def f(): 
    print s 
    s = "Me too." 
    print s 


s = "I hate spam." 
f() 
print s 

O/P

UnboundLocalError: local variable 's' referenced before assignment 

做，如果你尝试，你会得到上面的错误将一些值分配给s

，如果你尝试打印的s值会在函数内部打印