python - zip error: Invalid command arguments (cannot write zip file to terminal) -

i learning book bite of python. after typing in example in book

import os import time  # 1. files , directories backed # specified in list. # example on windows: # source = ['"c:\\my documents"', 'c:\\code'] # example on mac os x , linux: source = ['/home/username/downloads/books'] # notice had use double quotes inside string #  names spaces in it.  # 2. backup must stored in  # main backup directory # example on windows: # target_dir = 'e:\\backup' # example on mac os x , linux: target_dir = '/home/username/downloads/backup' # remember change folder using  # 3. files backed zip file. # 4. name of zip archive current date , time target = target_dir + os.sep + \         time.strftime('%y%m%d%h%m%s') + '.zip'  # create target directory if not present if not os.path.exists(target_dir):     os.mkdir(target_dir)    # make directory  # 5. use zip commond put files in zip archive zip_command = "zip - r {0} {1}".format(target, ' '.join(source))  # run backup print "zip command is:" print zip_command print "running:" if os.system(zip_command) == 0:     print 'successful backup to', target else:     print 'backup falied' 

i goe message zip error: invalid command arguments (cannot write zip file terminal) can not figure out goes wrong, type in same code in book. knows why happen?

the issue in zip command creating , there space between - , r . example -

zip_command = "zip - r {0} {1}".format(target, ' '.join(source))                     ^ notice space 

there should no space between - , r. example -

zip_command = "zip -r {0} {1}".format(target, ' '.join(source)) 

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also, suggest that, better use subprocess.call() rather os.system , providing list of arguments command. example -

import subprocess zip_command = ['zip','-r',target] s in source:     zip_command.append(s) subprocess.call(zip_command) 

it have been easier see error way.