Python 中的局部变量和全局变量

 

两个例子:

Python

i = 0 def printi(): global i # 定义i为全局变量 i += 1 print(i) printi() # 调用函数正常输出,1 例子二: i = 0 def printi(): i += 1 print(i) printi() # printi会在局部作用域中进行查找,找不到就报错.local variable 'i' referenced before assignment """报错 UnboundLocalError: local variable 'i' referenced before assignment """

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i = 0 def printi ( ) :      global i # 定义i为全局变量      i += 1      print ( i )     printi ( ) # 调用函数正常输出,1   例子二 :   i = 0 def printi ( ) :      i += 1      print ( i )     printi ( ) # printi会在局部作用域中进行查找 ,找不到就报错 . local variable 'i' referenced before assignment """报错 UnboundLocalError: local variable 'i' referenced before assignment """

 

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