This is because, even though Var1 exists, you're also using an assignment statement on the name Var1 inside of the function ( Var1 -= 1 at ... ... <看更多>

The unboundlocalerror: local variable referenced before assignment is raised when you try to use a variable before it has been assigned in the local context. ... <看更多>

This error is pretty much explained here and it helped me to get assignments and return values for all variables. ... <看更多>