Help with Python UnboundLocalError: local variable referenced before assignment

Question

I have post the similar question before,however,I think I may have misinterpreted my question,so may I just post my origin code here,and looking for someone can help me,I am

Answer 1

Put an additional global statement containing all your globals after each def statement. Otherwise, all globals are transformed into locals within your def without it.

def update_v(n,vs,ve,ms,me,dt,fs,fe):
    global vs, ve, ...