Modify the function variables from inner function in python -

it's ok , print outer function variable a

def outer(): = 1 def inner(): print

it's ok outer function array a , append something

def outer(): = [] def inner(): a.append(1) print

however, caused problem when tried increment integer:

def outer():     = 1     def inner():         += 1 #or = + 1         print  >> unboundlocalerror: local variable 'a' referenced before assignment

why happen , how can accomplish goal (increase integer)?

workaround python 2:

def outer(): = [1] def inner(): a[0] += 1 print a[0]

python function variables scope

Three