Directory Listing with size (no sub folders) via Python 08

import os
import sys

def get_size(start_path = '.'):
    total_size = 0
    for dirpath, dirnames, filenames in os.walk(start_path):
        for f in filenames:
            fp = os.path.join(dirpath, f)
            total_size += os.path.getsize(fp)

    if total_size == 0 and os.path.isfile(start_path):
        total_size += os.path.getsize(start_path)

    return total_size

def listContents(start_path = '.'):
    print('running on dir "' + start_path + '"')
    dirName = os.path.basename(os.path.abspath(start_path))

    contents = os.listdir(start_path)
    f = open('output_' + dirName + '.csv', 'w')
    for c in contents:
        str(c.encode('utf8'))
        f.write(', ')
        f.write(str(get_size(start_path + '/' + c) / 1024 / 1024/ 1024) + '\n')
    f.close();

if len(sys.argv) > 1:
    listContents(sys.argv[1])
else:
    listContents();