argparse
Python's standard-library module for building command-line interfaces that parse arguments and flags.
argparse turns command-line input into usable values. You create an ArgumentParser, declare the arguments you expect with add_argument, and call parse_args() to read them. It handles positional arguments, optional --flags, type conversion, and an automatic -h help screen.
It saves you from hand-parsing sys.argv and gives users clear errors when they get the command-line arguments wrong.
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("name")
parser.add_argument("--shout", action="store_true")
args = parser.parse_args(["Ada", "--shout"])
print(args.name, args.shout)
Output
Ada True
Where this shows up in real Python
argparse powers real command-line tools: named flags, defaults, types, and an auto-generated --help.
Commonly used argparse tools
ArgumentParser()— create the parser.add_argument('path')— declare a positional argumenttype=int, default=...— convert and supply a fallbackaction='store_true'— an on/off flag.parse_args()— read the arguments into an object
Official documentation: Python Library Reference: argparse