make_help.py

import sys
import re

DOCUMENTATION = re.compile(r"((?:^# [^\n]+\n)+)^([^#:]+):", re.MULTILINE)
STRIP = re.compile(r"(\n)|(#)")

YELLOW = '\033[93m'
GREEN = '\033[32m'
RESET = '\033[0m'
BOLD = '\033[01m'

print(f"{BOLD}Usage:{RESET}")
print(f"  make {GREEN}[command]{RESET}")
print(f"{BOLD}Commands:{RESET}")

commands = {}

for makefile in sys.argv[1:]:
    with open(makefile, "r") as f:
        content = f.read()
    for match in DOCUMENTATION.findall(content):
        commands[match[1]] = re.sub(STRIP, "", match[0])

largest = 0
for task in commands:
    current = len(task)
    if current > largest:
        largest = current

for task, message in commands.items():
    print(f"{YELLOW}{task.rjust(largest)}{RESET} -{message}")

Makefile

# Some help text here
thing:
	@echo boooo

# Show this help.
help:
	@python make_help.py $(MAKEFILE_LIST)