global variable

http://stackoverflow.com/questions/423379/global-variables-in-python

globvar = 0

def set_globvar_to_one():

    global globvar    # Needed to modify global copy of globvar

    globvar = 1

def print_globvar():

    print globvar     # No need for global declaration to read value of globvar

set_globvar_to_one()

print_globvar()       # Prints 1