lines.py

#!/usr/bin/env python

import multiprocessing
import random
import string
import time


def fill_output():
    to_fill = num_lines - len(last_output_per_process)
    for _ in range(to_fill):
        print()


def clean_up():
    for _ in range(num_lines):
        print("\x1b[1A\x1b[2K", end="")  # move up cursor and delete whole line


def log(repo_name, *args):
    with terminal_lock:
        last_output_per_process[repo_name] = " ".join(str(arg) for arg in args)
        clean_up()
        sorted_lines = last_output_per_process.items()
        for repo_name, last_line in sorted_lines:
            print(f"{repo_name}: {last_line}")
        fill_output()


def randsleep():
    time.sleep(random.randint(1, 2))


def func(repo_name):
    log(repo_name, "Starting")
    randsleep()
    log(repo_name, "Installing")
    randsleep()
    log(repo_name, "Building")
    randsleep()
    log(repo_name, "Instrumenting")
    randsleep()
    log(repo_name, "Running tests")
    randsleep()
    log(repo_name, f"Result in {repo_name}.json")
    with terminal_lock:
        del last_output_per_process[repo_name]


repos = [f"repo{letter}" for letter in string.ascii_uppercase]
num_procs = multiprocessing.cpu_count()
num_lines = min(len(repos), num_procs)
with multiprocessing.Manager() as manager:
    last_output_per_process = manager.dict()
    terminal_lock = manager.Lock()
    # Make space for our output
    fill_output()
    with multiprocessing.Pool(num_procs) as pool:
        pool.map(func, repos, chunksize=1)
    clean_up()