event_probability.py

#! /usr/bin/python3
# ==================================================================
#
#   import random as random
#
#   if random.random() < .70:
#       print('A wins')
#   else:
#       print('B wins')
#
# The code means that A has an 70% chance of being selected
# (wining).
#
# The return value of random.random() is uniformly distributed
# across the range [0.0, 1.0) (from 0.0 inclusive to 1.0
# exclusive). random.random() has an equal chance of hitting
# any value in that range. This means that statistically 70%
# of the time a values below 0.70 occurs.
#
# ==================================================================

import random as R

event_probability = 0.70

number_of_tries = 1_000_000

true_count = 0

for _ in range(number_of_tries):
    if R.random() < event_probability:
        true_count += 1

calculated_probability = float(true_count) / float(number_of_tries)

print()
print('theoritical probability = {}'.format(event_probability))
print('number of tries         = {}'.format(number_of_tries))
print('calculated true count   = {}'.format(true_count))
print('calculated probability  = {}'.format(calculated_probatility))
print()