[SOLVED] Python IO – show read speed interactively

Python IO – show read speed interactively

is it possible to show reading speed interactively when reading a file?

The reason is that I would like to measure the speed when reading a file from network drive via Python and compare it against copying the file to local drive manually.

Let's say I have a simple open read function:

with open("path/to/network/drive/file", "rb") as f: # Show speed interactively when reading
    # do stuff

Thanks!

Solution

You can take advantage of the popular tqdm package, which displays not only a progress bar but also the speed of the progress, by creating a file-like object that wraps an actual file object with a read method that updates a tqdm object through its update method:

import os
from tqdm import tqdm

class TQDMFileReader:
    def __init__(self, file):
        self.file = file
        self.tqdm = tqdm(total=os.stat(file.fileno()).st_size, unit='bytes')

    def read(self, size):
        value = self.file.read(size)
        self.tqdm.update(len(value))
        return value

so that with:

from time import sleep

with open(__file__, 'rb') as file:
    reader = TQDMFileReader(file)
    while reader.read(20):
        sleep(.2)

you get an output like:

100%|████████████████████████████████████████| 446/446 [00:04<00:00, 96.37bytes/s]

Demo: https://replit.com/@blhsing1/OverdueJoyousBooleanalgebra