python nonlocal

1def to_string(node):
2    def actual_recursive(node):
3        nonlocal a_str		# ~global, can modify surrounding function's scope.
4        a_str += str(node.val)
5        if node.next != None:
6            actual_recursive(node.next)
7    a_str = ''
8    actual_recursive(node)
9    return a_str

1globvar = 0
2
3def set_globvar_to_one():
4    global globvar    # Needed to modify global copy of globvar
5    globvar = 1
6
7def print_globvar():
8    print(globvar)     # No need for global declaration to read value of globvar
9
10set_globvar_to_one()
11print_globvar()       # Prints 1