Variable Scope for Scripts

[snippsat]

, is using global variables the way I have a concern?

No really,i like to do if __name__ == '__main__': as a natural way to see that script end.
Also make it easier to test,if import code it don't automatically run.
So here is not much exposed before doing the final call.

def read_data_from_file(file_to_read):
    #code to read from file and build list
    return list_of_files

def copy_files_to_backup_folder(file_to_copy):
    #code to copy files
    pass

def is_backup_successful():
    #code to verify that the a compressed file was created
    pass

def write_log_file(file_name):
    #code to generate a log file
    pass

def backup(file_name):
    files_to_backup = read_data_from_file(file_name)
    for f in files_to_backup:
        copy_files_to_backup_folder(f)
    is_backup_successful()
    write_log_file(file_name)

if __name__ == '__main__':
    # Here do last step that start it
    file_name = "some/path/to/file"
    backup(file_name)