Python local assignment rules _python

Copy Code code as follows:

MyVar = 1

Def myfunc ():
MyVar + 1

MyFunc ()

An error is prompted:

Unboundlocalerror:local variable ' myVar ' referenced before assignment

Python assumes that if you assign a value to a variable anywhere in the body of the function, Python adds the name to the local namespace.

Statement MyVar + = 1 assigns a value to the name MyVar, the MyVar is part of the local namespace of the function MyFunc, and it does not currently have an associated value, resulting in an error.

WORKAROUND: Use global statement

Copy Code code as follows:

MyVar = 1

Def myfunc ():
Global MyVar
MyVar + 1

MyFunc ()

Scoping Search Rules:

L: Native (local)

E: Closed (eclosing)

G: Overall (global)

B: Built in (built-in)