Python Random Module
Python Random module generates random numbers in Python. These are pseudo-random numbers means they are not truly random.
This module can be used to perform random actions such as generating random numbers, printing random a value for a list or string, etc. It is an in-built function in Python.
List of all the functions Python Random Module
There are different random functions in the Random Module of Python. Look at the table below to learn more about these functions:
Function Name |
Description |
---|---|
seed() | Initialize the random number generator |
getstate() | Returns an object with the current internal state of the random number generator |
setstate() | Used to restore the state of the random number generator back to the specified state |
getrandbits() | Return an integer with a specified number of bits |
randrange() | Returns a random number within the range |
randint() | Returns a random integer within the range |
choice() | Returns a random item from a list, tuple, or string |
choices() | Returns multiple random elements from the list with replacement |
sample() | Returns a particular length list of items chosen from the sequence |
random() | Generate random floating numbers |
uniform() | Return a random floating number between two numbers both inclusive |
triangular() | Return a random floating point number within a range with a bias towards one extreme |
betavariate() | Return a random floating point number with beta distribution |
expovariate() | Return a random floating point number with exponential distribution |
gammavariate() | Return a random floating point number with a gamma distribution |
gauss() | Return a random floating point number with Gaussian distribution |
lognormvariate() | Return a random floating point number with a log-normal distribution |
normalvariate() | Return a random floating point number with normal distribution |
vonmisesvariate() | Return a random floating point number with von Mises distribution or circular normal distribution |
paretovariate() | Return a random floating point number with a Pareto distribution |
weibullvariate() | Return a random floating point number with Weibull distribution |
Random Module in Python Examples
Let’s discuss some common operations performed by Random module in Python.
Example 1: Printing a random value from a list in Python.
This code uses the random
module to select a random element from the list list1
using the random.choice()
function. It prints a random element from the list, demonstrating how to pick a random item from a sequence in Python.
Python3
import random list1 = [ 1 , 2 , 3 , 4 , 5 , 6 ] print (random.choice(list1)) |
3
Example 2: Creating random numbers with Python seed() in Python.
As stated above random module creates pseudo-random numbers. Random numbers depend on the seeding value. For example, if the seeding value is 5 then the output of the below program will always be the same. Therefore, it must not be used for encryption.
The code sets the random number generator’s seed to 5 using random.seed(5)
, ensuring reproducibility. It then prints two random floating-point numbers between 0 and 1 using random.random()
. The seed makes these numbers the same every time you run the code with a seed of 5, providing consistency in the generated random values.
Python3
import random random.seed( 5 ) print (random.random()) print (random.random()) |
0.6229016948897019 0.7417869892607294
Generate Random Numbers in Python
random.randint() method is used to generate random integers between the given range.
Syntax: randint(start, end)
Example: Creating random integers
This code uses the ‘random'
module to generate random integers within specific ranges. It first generates a random integer between 5 and 15 (inclusive) and then between -10 and -2 (inclusive). The generated integers are printed with appropriate formatting.
Python3
import random r1 = random.randint( 5 , 15 ) print ( "Random number between 5 and 15 is % s" % (r1)) r2 = random.randint( - 10 , - 2 ) print ( "Random number between -10 and -2 is % d" % (r2)) |
Random number between 5 and 15 is 10 Random number between -10 and -2 is -2
Generate Random Float numbers in Python
A random.random() method is used to generate random floats between 0.0 to 1.
Syntax: random.random()
Example:
In this code, we are using the random
function from the ‘random'
module in Python. It prints a random floating-point number between 0 and 1 when you call random()
.
Python3
from random import random print (random()) |
0.8443722499369146
Randomly Select Elements from a List in Python
Random sampling from a list in Python (random.choice, and sample)
Example 1: Python random.choice() function is used to return a random item from a list, tuple, or string.
The code uses the random.choice()
function from the random
module to randomly select elements from different data types. It demonstrates selecting a random element from a list, a string, and a tuple. The chosen elements will vary each time you run the code, making it useful for random selection from various data structures.
Python3
import random list1 = [ 1 , 2 , 3 , 4 , 5 , 6 ] print (random.choice(list1)) string = "Beginner" print (random.choice(string)) tuple1 = ( 1 , 2 , 3 , 4 , 5 ) print (random.choice(tuple1)) |
4 k 5
Example 2: Python random.sample() function is used to return a random item from a list, tuple, or string.
Syntax: random.sample(sequence, length)
This code utilizes the sample
function from the ‘random'
module to obtain random samples from various data types. It selects three random elements without replacement from a list, a tuple, and a string, demonstrating its versatility in generating distinct random samples. With each execution, the selected elements will differ, providing random subsets from the input data structures.
Python3
from random import sample list1 = [ 1 , 2 , 3 , 4 , 5 ] print (sample(list1, 3 )) list2 = ( 4 , 5 , 6 , 7 , 8 ) print (sample(list2, 3 )) list3 = "45678" print (sample(list3, 3 )) |
[4, 2, 3] [4, 7, 8] ['6', '4', '8']
Shuffle List in Python
A random.shuffle() method is used to shuffle a sequence (list). Shuffling means changing the position of the elements of the sequence. Here, the shuffling operation is inplace.
Syntax: random.shuffle(sequence, function)
Example: Shuffling a List
This code uses the random.shuffle()
function from the ‘random
'
module to shuffle the elements of a list named ‘sample_list'
. It first prints the original order of the list, then shuffles it twice. The second shuffle creates a new random order, and the list’s content is displayed after each shuffle. This demonstrates how the elements are rearranged randomly in the list with each shuffle operation.
Python3
import random sample_list = [ 1 , 2 , 3 , 4 , 5 ] print ( "Original list : " ) print (sample_list) random.shuffle(sample_list) print ( "\nAfter the first shuffle : " ) print (sample_list) random.shuffle(sample_list) print ( "\nAfter the second shuffle : " ) print (sample_list) |
Original list : [1, 2, 3, 4, 5] After the first shuffle : [3, 2, 1, 5, 4] After the second shuffle : [2, 3, 1, 5, 4]
In this article we discussed about Python Random module, and also saw some examples of functions in random module in Python. Random module in Python is very important and contains very useful functions.
Hope this helps you in using Python Random module functions.