argparse - Command-Line Argument Parser

The argparse module makes it easy to write user-friendly command-line interfaces. It parses arguments defined in sys.argv, generates help and usage messages, and issues errors when users give invalid arguments.

🔍 Key Components

• argparse.ArgumentParser - Main parser class for command-line arguments
• argparse.Action - Base class for argument actions
• argparse.Namespace - Object to store parsed arguments
• argparse.FileType - Factory for file object arguments

🚀 Basic Usage

import argparse

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

# Add arguments
parser.add_argument('filename', help='Input filename')
parser.add_argument('--verbose', '-v', action='store_true', 
                   help='Enable verbose output')
parser.add_argument('--count', type=int, default=1,
                   help='Number of times to process')

# Parse arguments
args = parser.parse_args()

# Use arguments
if args.verbose:
    print(f"Processing {args.filename} {args.count} times")

📊 Argument Types

Type	Purpose	Example
Positional	Required arguments	filename
Optional	Flag arguments	--verbose, -v
Store	Store values	--output file.txt
Store True/False	Boolean flags	--verbose
Count	Count occurrences	-vvv
Append	List values	--file a.txt --file b.txt