Use tqdm with concurrent.futures?

Question

I have a multithreaded function that I would like a status bar for using tqdm. Is there an easy way to show a status bar with ThreadPoolExecutor? It is the parallelization part that is confusing me.

import concurrent.futures

def f(x):
    return f**2

my_iter = range(1000000)

def run(f,my_iter):
    with concurrent.futures.ThreadPoolExecutor() as executor:
        function = list(executor.map(f, my_iter))
    return results

run(f, my_iter) # wrap tqdr around this function?

Answer 1

You can wrap tqdm around the executor as the following to track the progress:

list(tqdm(executor.map(f, iter), total=len(iter))

Here is your example:

import time  
import concurrent.futures
from tqdm import tqdm

def f(x):
    time.sleep(0.001)  # to visualize the progress
    return x**2

def run(f, my_iter):
    with concurrent.futures.ThreadPoolExecutor() as executor:
        results = list(tqdm(executor.map(f, my_iter), total=len(my_iter)))
    return results

my_iter = range(100000)
run(f, my_iter)

And the result is like this:

16%|██▏           | 15707/100000 [00:00<00:02, 31312.54it/s]