Python global/local variables

Question

Why does this code work:

var = 0

def func(num):
    print num
    var = 1
    if num != 0:
        func(num-1)

func(10)

but this one give

Answer 1

In your second piece of code you have created a local variable in RHS and without defining it, you are assigning it to the LHS variable var which is global (a variable defined outside the function is considered global explicitly).

If your intention is to create a local variable inside the function and assign it to the value of the global variable, this will do the trick:

var = 0

def func(num):
    print num
    func.var = var # func.var is referring the local
                   # variable var inside the function func
    if num != 0:
        func(num-1)

func(10)