python區域性變數&全域性變數
阿新 • • 發佈:2020-07-18
全域性變數:
對於函式來講,可以被引用,也可以“增刪”(可變變數,列表、字典、集合),但不能被重新賦值:
name = {1,2,3,45} def test(): name.add(6) name.pop() print(globals()) print(locals()) print(name) test() #{'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external.SourceFileLoader object at 0x000001FCE4B41910>, '__spec__': None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>, '__file__': 'E:/pythondir/Day01/func.py', '__cached__': None, 'name': {2, 3, 6, 45}, 'test': <function test at 0x000001FCE4CF4040>}#{} #{2, 3, 6, 45}
重新賦值(先呼叫,再重新賦值):
name = {1,2,3,45} def test(): name.add(6) name=6 print(globals()) print(locals()) print(name) test() #Traceback (most recent call last): File "E:/pythondir/Day01/func.py", line 8, in <module> test() File "E:/pythondir/Day01/func.py", line 3, intest name.add(6) UnboundLocalError: local variable 'name' referenced before assignment
區域性變數:
在函式內優先呼叫區域性變數,沒找到區域性變數再呼叫全域性變數