1d:I[11492,["/_next/static/chunks/ff3bf7cc534b7523.js","/_next/static/chunks/d7b1323b03251853.js","/_next/static/chunks/22b06a55bae91926.js","/_next/static/chunks/21aa533c6f3694f4.js"],"default"] 1e:T404,

Building CLIs with argparse

Simple Example

import argparse

# Create parser
parser = argparse.ArgumentParser(
    description='Process some files.'
)

# Add positional argument
parser.add_argument('filename', help='File to process')

# Add optional argument
parser.add_argument('-v', '--verbose', action='store_true',
                    help='Enable verbose output')

# Parse arguments
args = parser.parse_args()

print(f"Processing: {args.filename}")
if args.verbose:
    print("Verbose mode enabled")

Running the Script

$ python script.py data.txt
Processing: data.txt

$ python script.py data.txt --verbose
Processing: data.txt
Verbose mode enabled

$ python script.py --help
usage: script.py [-h] [-v] filename

Process some files.

positional arguments:
  filename       File to process

optional arguments:
  -h, --help     show this help message and exit
  -v, --verbose  Enable verbose output

1f:T41e,

Different Argument Types

Positional Arguments

import argparse

parser = argparse.ArgumentParser()

# Required positional
parser.add_argument('input_file')
parser.add_argument('output_file')

# Multiple values
parser.add_argument('numbers', nargs='+', type=int)

args = parser.parse_args()
# python script.py in.txt out.txt 1 2 3

Optional Arguments

import argparse

parser = argparse.ArgumentParser()

# Boolean flag
parser.add_argument('-v', '--verbose', action='store_true')
parser.add_argument('-q', '--quiet', action='store_true')

# With value
parser.add_argument('-o', '--output', default='out.txt')
parser.add_argument('-n', '--count', type=int, default=1)

# Required optional (sounds odd but useful)
parser.add_argument('-c', '--config', required=True)

# Choices
parser.add_argument('-f', '--format',
                    choices=['json', 'csv', 'xml'],
                    default='json')

args = parser.parse_args()

20:T448,

Advanced argparse

Subcommands

import argparse

parser = argparse.ArgumentParser()
subparsers = parser.add_subparsers(dest='command')

# 'add' subcommand
add_parser = subparsers.add_parser('add', help='Add a new item')
add_parser.add_argument('name')

# 'remove' subcommand
remove_parser = subparsers.add_parser('remove', help='Remove an item')
remove_parser.add_argument('id', type=int)

args = parser.parse_args()

if args.command == 'add':
    print(f"Adding: {args.name}")
elif args.command == 'remove':
    print(f"Removing ID: {args.id}")

File Arguments

import argparse

parser = argparse.ArgumentParser()

# Automatically opens file for reading
parser.add_argument('infile', type=argparse.FileType('r'))

# Opens file for writing
parser.add_argument('-o', '--output',
                    type=argparse.FileType('w'),
                    default='-')  # '-' means stdout

args = parser.parse_args()
content = args.infile.read()
args.output.write(content.upper())

Basic argparse

Basic argparse

Building CLIs with argparse

Simple Example

Running the Script