with 'nonlocal' inner functions(ie;nested inner functions) can get read & 'write' permission for that specific variable of the outer parent function. And nonlocal can be used only inside inner functions eg:
a = 10
def Outer(msg):
a = 20
b = 30
def Inner():
c = 50
d = 60
print("MU LCL =",locals())
nonlocal a
a = 100
ans = a+c
print("Hello from Inner",ans)
print("value of a Inner : ",a)
Inner()
print("value of a Outer : ",a)
res = Outer("Hello World")
print(res)
print("value of a Global : ",a)