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Functions & basics

Reusable building blocks — parameters, returns, scope, and clear function design.

4 matches

Format CLI help text in Python

Build a readable usage string for a command-line tool, aligning flags and wrapping descriptions with the textwrap module.

cli textwrap formatting

Python

import textwrap


def format_help(command_name: str, description: str, options: list[tuple[str, str]]) -> str:
    """Format CLI help text into a readable usage string."""
    header = f"Usage: {command_name} [OPTIONS]"
    lines = [header, "", description, "", "Options:"]

    for flag, help_text in options:
        …

12 0 Open

Functions & basics easy

How to Add a Dry Run Flag to a Python CLI Command

Build a Python CLI command with a --dry-run flag that previews actions and exits before making real changes.

argparse cli dry-run

Python

import argparse
import sys

def main():
    parser = argparse.ArgumentParser(description="Sample CLI command with dry-run flag")
    parser.add_argument("--name", required=True, help="Name to greet")
    parser.add_argument("--dry-run", action="store_true", dest="dry_run",
                        help="Show what would…

11 0 Open

Functions & basics medium

How to Build a Subcommand Parser Tree with argparse in Python

Create a CLI with nested subcommands (like git) using argparse subparsers, where each subcommand maps to its own handler function.

argparse cli subparsers

Python

import argparse


def cmd_add(args):
    print(f"Adding {args.num1} + {args.num2} = {args.num1 + args.num2}")


def cmd_sub(args):
    print(f"Subtracting {args.num1} - {args.num2} = {args.num1 - args.num2}")


def main():
    parser = argparse.ArgumentParser(prog="calculator")
    subparsers = parser.add_subparsers(d…

12 0 Open

Functions & basics easy

How to Validate CLI Integer Option Within a Range in Python

Use argparse with integer type and bounds checking to validate a command-line option falls within a specified min-max range.

argparse cli validation

Python

import argparse

def main():
    parser = argparse.ArgumentParser(description="Validate an integer within a range.")
    parser.add_argument("--value", type=int, required=True, help="Integer to validate")
    parser.add_argument("--min", type=int, default=0, help="Minimum allowed value")
    parser.add_argument("--max…

13 0 Open

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