A script containing functions to calculate minimum required sample size for experiments:

calculate_minimum_sample_size.py

#! /usr/bin/env python
import math
import statistics

def binomial_required_sample_size(p1, p2, min_diff=5e-4, include_continuity_correct=True, two_sided=True):
    """derived from: https://www.itl.nist.gov/div898/handbook/prc/section2/prc242.htm"""
    z_alpha = 1.95
    if two_sided:
        z_alpha = 2.24
    z_beta = 0.89

    p1_std = math.sqrt(p1 * (1.0 - p1))
    p2_std = math.sqrt(p2 * (1.0 - p2))
    n = pow((z_alpha * p1_std + z_beta * p2_std) / (min_diff), 2)
    if include_continuity_correct:
        n += 1/min_diff
    return n

As of current revision this is calculated with an assumed minimum difference of 1/2 of 1%.

Using itl.nist documentation for its calculation