single-line 1.0.0

A context manager to facilitate printing messages to the same line

single-line

A context manager to facilitate printing messages to the same line.

Installation

pip install single-line

Usage

Using the SingleLine context manager all calls to its print method will print the message to the same line. A common use case will be to use it in conjuction with a for loop as follows.

from time import sleep
from faker import Faker
from single_line import SingleLine

with SingleLine() as line:
    for _ in range(25):
        line.print(Faker().sentence())
        sleep(.15)

Setting message_when_done parameter will print a prescribed message when the context is done. The print method also supports printing colored messages via the colorama module, just pass the method an optional color parameter consiting of a dictionary describing the fore, back and style you wish to the message to be printed with.

from time import sleep
from faker import Faker
from colorama import Fore
from single_line import SingleLine

with SingleLine(message_when_done='done') as line:
    for _ in range(25):
        line.print(Faker().sentence(), color={'fore': Fore.YELLOW})
        sleep(.15)

By default messages will be printed out to sys.stdout but you can print to any object with a write(string) method. This example also shows the extent of using colors when printing messages.

import sys
import random
from time import sleep
from faker import Faker
from single_line import SingleLine
from colorama import Fore, Back, Style

def get_random_fore():
    return random.choice([Fore.BLACK, Fore.RED, Fore.GREEN, Fore.YELLOW, Fore.BLUE, Fore.MAGENTA, Fore.CYAN, Fore.WHITE])

def get_random_back():
    return random.choice([Back.BLACK, Back.RED, Back.GREEN, Back.YELLOW, Back.BLUE, Back.MAGENTA, Back.CYAN, Back.WHITE])

def get_random_style():
    return random.choice([Style.NORMAL, Style.DIM, Style.BRIGHT])

with SingleLine(stream=sys.stderr) as line:
    for _ in range(25):
        line.print(Faker().sentence(), color={'fore': get_random_fore(), 'back': get_random_back(), 'style': get_random_style()})
        sleep(.15)

You can also use the SingleLine context manager to display messages when executing asyncio methods.

import asyncio
import random
from faker import Faker
from single_line import SingleLine

async def do_some_work(worker, fake, line):
    for index in range(random.randint(10, 35)):
        await asyncio.sleep(random.choice([.5, .1, .25]))
        line.print(f'worker{worker} {fake.sentence()}')

async def run(line):
    await asyncio.gather(*(do_some_work(worker, Faker(), line) for worker in range(5)))

with SingleLine(message_when_done='done with asyncio') as line:
    asyncio.run(run(line))

Development

Clone the repository and ensure the latest version of Docker is installed on your development server.

Build the Docker image:

docker image build \
-t single-line:latest .

Run the Docker container:

docker container run \
--rm \
-it \
-v $PWD:/code \
single-line:latest \
bash

Execute the build:

pyb -X