async_bar.py

#!/usr/bin/python
import datetime
import time
import sys
import asyncio

import i3ipc

def getDate():
    today = datetime.date.today()
    return today.strftime("%A %B %d, %Y")

def getTime():
    now = datetime.datetime.now()
    return now.strftime("%I:%M %p")

def getWorkspaces(i3):
    output = sys.argv[1]
    workspaces = i3.get_workspaces()
    names = [workspace["name"] for workspace in filter(lambda ws: ws.output==output, workspaces)]
    return " ".join(names)

def run_async(fn, args, vals):
    future = asyncio.Future()
    args.insert(0, future)
    args.insert(1, vals)
    asyncio.ensure_future(fn(*args))
    future.add_done_callback(lambda fut: print_bar(fut, vals))

@asyncio.coroutine
def asyncDate(future, vals):
    yield from asyncio.sleep(500)
    future.set_result({"date": getDate()})
    run_async(asyncDate, [], vals)

@asyncio.coroutine
def asyncTime(future, vals):
    yield from asyncio.sleep(15)
    future.set_result({"time": getTime()})
    run_async(asyncTime, [], vals)

@asyncio.coroutine
def asyncWorkspaces(future, vals, i3):
    yield from asyncio.sleep(0.1)
    future.set_result({"workspaces": getWorkspaces(i3)})
    run_async(asyncWorkspaces, [i3], vals)

def print_bar(future, vals):
    vals.update(future.result())
    output = "{left}{f_white}{b_black} {date} {center} {workspaces} {right} {time} {f_clear}".format(**vals)
    print(output)
    sys.stdout.flush()

i3 = i3ipc.Connection()
loop = asyncio.get_event_loop()

vals = {
    "left": "%{l}",
    "right": "%{r}",
    "center": "%{c}",
    "f_white": "%{F#FF000000}",
    "f_clear": "%{F-}",
    "b_black": "%{B#FFFFFFFF}",
    "date": getDate(),
    "time": getTime(),
    "workspaces": getWorkspaces(i3)
    }

output = "{left}{f_white}{b_black} {date} {center} {workspaces} {right} {time} {f_clear}".format(**vals)
print(output)
sys.stdout.flush()

run_async(asyncDate, [], vals)
run_async(asyncTime, [], vals)
run_async(asyncWorkspaces, [i3], vals)

loop.run_forever()