Python Random - Flip a Coin

Python Flip a Coin

In this tutorial, we shall learn to write a function, that randomly returns True or False corresponding to a Head or Tail for the experiment of flipping a coin.

To randomly select on of the two possible outcomes, you can use random.choice() function, with the two outcomes passed as list elements. Or you can use random.random() function that returns a floating point and decide one of the two possible outcomes based on the output range.

Programs

1. Python function to Flip a coin

In this example, we shall write a function, called flipCoin(). This function returns True or False randomly with each call.

As already mentioned in the introduction, we shall call random.choice() with the list [True, False] passed as argument.

Python Program

import random
import string

def flipCoin():
    return random.choice([True,False])

for i in range(0,5):
    print(flipCoin())

We have called flipCoin() function multiple times using a Python For Loop to demonstrate the randomness of the returned value.

Output

False
True
True
False
True

Please note that there is no control on the number of Trues or Falses returned for a limited function calls of flipCoin().

As the number of times you flip a coin tend to a very large number or infinity, the probability of Head or False tend to 0.5.

2. Flip a coin experiment using random.random()

random.random() function returns a floating value in the range (0,1). You can decide that the flipping a coin results in Head if random.random() returns a value in between 0 and 0.5, and a Tail if random.random() returns a value between 0.5 and 1.

In this example, we shall use random.random() function to programmatically implement the experiment of flipping a coin.

Python Program

import random
import string

def flipCoin():
    f = random.random()
    return True if f<0.5 else False

for i in range(0,5):
    print(flipCoin())

Output

True
False
False
True
False

Summary

In this tutorial of Python Examples, we learned how to use random package to programmatically implement the experiment: Flip a Coin.