I'd like to assign an "external" value for a global variable in a standalone Python program from a command line parameter and let my functions manipulate it (please disregard the fact that using global variables is discouraged in general). I have tried like the following:
def my_function():
global global_var
global_var+=1
def main(argv):
global_var = sys.argv[1]
my_function()
if __name__ == "__main__":
main(sys.argv)
But it doesn't work because of the following reason:
NameError: global name 'global_var' is not defined
The problem occurs in the global global_var line in my_function, the function seemingly cannot recognize this as global despite the explicit qualification as like this. I guess that this is because my global_var doesn't exist before my_function()'s definition. But I cannot define my global_var at the beginning of the code (before my_function()) either because main() should stand at the end and main() parses the program parameters. Right?
