CODEWITHSUNDEEP
python-3.xargparse
spk
spk

Reputation: 173

Using argparse arguments in different ways

i'm currently studying the argparse module and i want my program to behave like this:

$ python cldir.py # this should delete all .meta files in ~/downloads 

$ python cldir.py -d /path/name/ # delete all .meta files in /path/name

$ python cldir.py -d /path/name -e txt # should delete all .txt files in /path/name

Now, i know i need to use another argument for the file extension (-e in this case), but i would like to know how i can make the -d switch to behave as shown above.

Here is my code so far:

#!/usr/bin/env python

import argparse
import os
import glob

version = "0.1.1"

parser = argparse.ArgumentParser(
    description = 'cldir: clear a directory from .meta and other unwanted files')

# arguments list

parser.add_argument('-v', '--version', action='version', version = version)

parser.add_argument('-d', '--direct', action = 'store_true')

args = parser.parse_args()

if args.direct == False:
    path = os.environ['HOME'] + '/downloads/'
    files = glob.glob(path + '*.meta')

    if len(files) == 0:
        print('No .meta files found in ~/downloads')
    else:
        for f in files:
            os.remove(f)
    print('%d file(s) deleted' %len(files))

else:
    print(args.direct)

The else: print(args.direct) is just for testing until i achieve the desired behaviour.

Any other observations/suggestions are highly welcome as well since i'm new to python.

Upvotes: 1

Views: 397

Answers (3)

hpaulj
hpaulj

Reputation: 231738

Using two optionals arguments lets your user specify the directory and extension in either order, or specify one, and let the other be the default:

p.add_argument('-d','--dir',default='default_dir')
p.add_argument('-e','--ext',default='meta')

Input: '' produces: Namespace(dir='default_dir', ext='meta')
'-d otherdir' => Namespace(dir='otherdir', ext='meta')
'-d otherdir -e txt' => Namespace(dir='otherdir', ext='txt')
'-e txt' => Namespace(dir='default_dir', ext='txt')

Blocking the use of -e before or without -d is possible, but probably not worth the extra code. However it is the default behavior with positionals.

Or the two arguments could be '?' positionals

p.add_argument('dir',default='default_dir',nargs='?')
p.add_argument('ext',default='meta',nargs='?')

Inputs producing the same namespaces would be '', 'otherdir', 'otherdir txt'. In this case specifying ext is contingent on specifying dir.

I don't think a store_true -d argument adds anything to the definition.

Upvotes: 1

unutbu
unutbu

Reputation: 880927

Use -d to let the user supply a path. You can set a default path with the default parameter. Similarly, you can set the default value for the -e option to 'meta'.

import argparse
import os
import glob

version = "0.1.1"

parser = argparse.ArgumentParser(
    description = 'cldir: clear a directory from .meta and other unwanted files')

# arguments list

parser.add_argument('-v', '--version', action='version', version = version)

parser.add_argument('-d', '--directory', default=os.path.expanduser('~/downloads'),
                    help='directory to be cleaned')

parser.add_argument('-e', default='meta', help='extension')

args = parser.parse_args()
print(args)
path = os.path.join(args.directory)
files = glob.glob(path + '*.{}'.format(args.e))

if len(files) == 0:
    print('No .meta files found in ~/downloads')
else:
    for f in files:
        os.remove(f)
    print('%d file(s) deleted' %len(files))

Upvotes: 1

chepner
chepner

Reputation: 532418

Make -d a simple 'store' argument with a default value.

parser.add_argument('--direct', '-d', default=os.environ['HOME'] + '/downloads/')

Then use args.direct as the path to pass to glob.glob.

Upvotes: 1

Related Questions