Unexpected output with glob.glob

Question

Im trying to provide wildcard support to one of CLI scripts and I am using pythons glob module for it. For a test i tried this:

>>> import glob
>>> for f in glob.glob('/Users/odin/Desktop/test_folder/*.log'):
...     print f
...
/Users/odin/Desktop/test_folder/test1.log
/Users/odin/Desktop/test_folder/test2.log
/Users/odin/Desktop/test_folder/test3.log

This works perfectly and gives the right output as i do have the 3 files given above. However when I have the same code under my argument in the CLI it fails. I do this

#code...
parser.add_argument( "-f", "--file", type=str, help="Full path to the file to upload." )
#code...
if args.file:
    for f in glob.glob(args.file):
        _upload_part(f)

I run this as

python cli.py -f /Users/odin/Desktop/test_folder/*.log

This gives me the error:

cli.py: error: unrecognized arguments: /Users/odin/Desktop/test_folder/test2.log /Users/odin/Desktop/test_folder/test3.log

I dont understand why all files are being added to the argument at once when I am going through the list one by one.

EDIT-

nargs was a step in the right direction but now this error shows up:

 `Traceback (most recent call last):
      File "cli.py", line 492, in <module>
        for f in glob.glob(args.file):
      File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/glob.py", line 27, in glob
        return list(iglob(pathname))
      File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/glob.py", line 38, in iglob
        dirname, basename = os.path.split(pathname)
      File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/posixpath.py", line 92, in split
        i = p.rfind('/') + 1
    AttributeError: 'list' object has no attribute 'rfind'`

Answer 1

Here's what your script receives:

python cli.py -f file1 file2 file3 fileN

Where N is a total number of files matched by that pattern (Shell expands wildcards automatically). On the other hand, your file argument is configured to receive just one file/pattern, thus the simplest (and the best, in my opinion) solution is to add the nargs='+' argument :

parser.add_argument('-f', '--file', type=str, help='...', nargs='+')
# code
for f in args.file:
    print(f)

This will allow you to remove all glob calls and if args.file checks.

Another option is to quote your command line argument:

python cli.py -f '/Users/odin/Desktop/test_folder/*.log'