Progress Counter in Python - wrote it before discovering tqdm

percentage_counter.py

from typing import List
from datetime import datetime, timedelta


class PercentageCounter:
    """Counter for stepping percentages over an arbitrary number
    e.g. total = 10, step = 0.15 (15%)
    counter.next(1) # progress is 10%, returns nothing
    counter.next(2) # progress is 20%, returns 15
    counter.next(3) # progress is 30%, returns nothing (has to exceed step)
    counter.next(4) # progress is 40%, returns 30
    …
    """

    def __init__(self, total, step=0.01):
        self.total = total
        self.step = step
        self.current = 0

        self.previous_date = None
        self.time_diff_avg = timedelta()

    def next_percentage(self, progress) -> List[str]:

        if self.previous_date:
            weighted_avg = 5
            new_diff = datetime.utcnow() - self.previous_date
            new_total = self.time_diff_avg * (weighted_avg - 1) + new_diff
            self.time_diff_avg = new_total / weighted_avg
        self.previous_date = datetime.utcnow()

        percentage = progress / self.total
        done = []
        while self.current + self.step < percentage:
            self.current += self.step
            eta = self.time_diff_avg * (self.total - progress)
            done.append(f"{round(self.current * 100):02}% Done... (ETA {eta})")
        return done