my_var = 27

def my_function(param1=123, param2='Python'):
    for key,val in locals().items():
        print('key {}: {}'.format(key, str(val)))
    my_var = my_var + 1     # causes an error!

def better_function(param1=123, param2='Python'):
    global my_var
    for key,val in locals().items():
        print('key {}: {}'.format(key, str(val)))
    my_var = my_var + 1    
    print('my_var:',my_var)



# my_function(123456, 765432.0)
better_function()