In python, variables defined in a function is only local to that function.

def myfunct():
    i = 1
    return "Hello World"
 
i = 0
print myfunct()
print i

When you run the code above, it would spit out:

>>>
Hello
0
>>>

In order to manipulate a variable within the function defined in main, we need to use ‘global‘.

def myfunct():
    global i
    i = 1
    return "Hello World"
 
i = 0
print myfunct()
print i

When you run the code above, it would spit out:

>>>
Hello
1
>>>