# How to Generate Random Data in Python?

By | September 26, 2021 Knowing how to generate random data using Python can be very useful in many cases. You might need to generate random data for Email OPT in your web-application or you might be working with cryptography using Python where you need to generate random UUID. Similarly, there are many applications where you need to generate random data using Python. Generally, when it comes to generating random Data in Python, the first most library that comes to our mind is Python `random` module, but there are other two Standard modules in Python that can also be used to generate random data.

In this Python tutorial, I will walk you through the python Different code snippets to Generate random data in Python.

So open your best Python IDE or Text editor and follow along.

## Generate Random Number in Python

There are two modules in Python that can be used to generate random numbers.

For most of the cases, you will be using the Python `random` module to generate random numbers, but in case if you wish to generate strong random numbers for the secret password, security token, and cryptography there you should be using the Python secrets module.

### Generating random numbers with Python random module

In a random module, you get two methods `randint(start, end)` and `randrange(start, end, [steps])` to generate random numbers.

The `randint(start, end)` will generate a random number greater than and equal to start and smaller than equal to end.

The `randrange(start, end, step)` method will generate a random number between start and end with the interval of specified steps.

```import random

#random number >=20, and <= 300
print(random.randint(20, 300))

#random number >=20, <300 and 20,30,...290
print(random.randrange(20, 300, 10))
```

Output

```162
280```

### Generating random numbers with Python secrets module

Using the Python `secrets` modules `randbelow(n)` method we can generate a random number between o to n.

```import secrets

#random number o to 99
print(secrets.randbelow(100))```

Output

`78`

let’s say you want to generate 4 digits random number for OTP in Python, for that you can use the Python `randint()` or `randrange()` method.

```import random

#4 digit opt
otp = random.randint(1000, 9999)

print("Your Four Digit OTP is:", otp)
```

Output

```Your Four Digit OTP is: 8901
```

### Choose Random Data From the Elements

Let’s say you have a Python list or any other sequence of elements and you want to randomly pick elements from the sequence, in that case, you can use the Python random or secrets module.

### Randomly chooses or pick elements from a Python List or sequence using `random` module

In The Python random module, we have two method `choice()` and `choices()` to pick random elements from the sequence.

The `choice(sequence)` method pick a single random element from the sequence. and.

The `choices(sequence, k)` pick k numbers of random elements from the sequence and return a list of k random picks.

```import random

cards = ["ace", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "J", "K", "Q"]

#pick one
print(random.choice(cards))

#pick 3 cards
print(random.choices(cards, k =3))```

Output

```ten
['three', 'five', 'six']```

### Randomly chooses or pick an element from a Python List or sequence using secrets  module

In secrets module we also get the choice() method to randomly select one element from a Python list or sequence.

```import secrets
cards = ["ace", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "J", "K", "Q"]

#pick one
print(secrets.choice(cards))```

Output

```seven
```

Selecting random elements from a sequence can be very useful, we can use it in many applications such as generating random long secure passwords from letters.

Let’s generate a 14 characters long random password in Python

#Python program to generate random passwords

```import string
import secrets
import random

#"'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'"
letters_digits = string.ascii_letters + string.digits

#with random choices()

#with secrets choice
passwords_secrets = "".join([secrets.choice(letters_digits) for _ in range(14)])
```

Output

```14 characters long Randomly Generated Password: X6WrjhOYUmmmbI
14 characters long Randomly Generated Password: phx1opoYMj7QLg```

### Generate Random Floating Points Numbers

In the above example, we have only covered how to generate random Integer numbers, let’s say you want to generate random floating points or decimal points random number then what will we do?- the answer is simple we will use the random() method.

The random module itself provides a random() method that generates a random floating-point number between 0.0 to 1.0 whenever you call it.

```import random

print("Random Floating point number between 0.0 and 1.0 : ", random.random())```

Output

Random Floating point number between 0.0 and 1.0: 0.3365084727758496

From the output, you can see that the random() function only returns a randomly generated floating-point number between 0.0 to 1.0. In many cases, it might done the work for you, but there is a high chance that you want to generate a big floating-point number with fixed decimal point numbers.

To generate 1 digit floating point numbers we will multiply the returned random() result with 10, to get 2 digits floating-point number will multiply the randomly generated floating-point number with 100 and so on. And to small the size of decimal points, we will round the numbers using the Python round function.

```import random

#random floating number
num = random.random()*10000

print("Random Floating Number", round(num, 2))

```

Output

```Random Floating Number 6466.69
```

The random module also provides another method `uniform(start, end)` that print a random floating number N, where `start < = N <= end`

```import random

#random floating number
num = random.uniform(10, 10000)

print("Random Floating Number", round(num, 2))
```

Output

```Random Floating Number 3299.03
```

### Generate Random Data For Cryptography

Although the Python `random` module provides many methods to generate random data, but it is not secure and reliable, and in most cases, you will see that it return similar random data. And when we talk about cryptography there we require such logic or modules which can generate random and unique data for us.

Luckily in Python, we have inbuilt Python standard `os` and `secrets` modules that can be used to generate random data in different formats. But in cryptography and security, you will be using the Python `secrets` module more than `os`, because it provides more methods to create random data.

#### Generate Random bytes data for Cryptographic use using Python `os` module

In Python `os` module, we get the `urandom(N)` function that generates random bytes data of size that is suitable for cryptographic use. The bytes data returned by the `urandom()` function is Operating System specific.

Example

```import os

size= 20
#random crypto-safe bytes data
crypto_bytes = os.urandom(size)

print("Random Bytes Data for Crypto: ", crypto_bytes)```

Output

```Random Bytes Data for Crypto: b'^ ]l\x8b\x1c\x83m\x15\xd53f\xb3e\x14X\xfa\xfa\x08\xe6'
```

#### Generate Random bytes data for Cryptographic use using Python `secrets` module

The `secrets` module provides more methods to generate secure random token data in different data type formats.

`randbits(k)` method returns a randomly generated integer with K random bits.

`token_bytes(N)` method returns a randomly generated Nbytes long Byte string token.

`token_hex(N)`method returns a randomly generated Nbytes long Hexadecimal string token.

`token_urlsafe(N)` method returns a randomly generated Nbytes long Base64 encoded text.

```import secrets

N= 18

crypto_bytes = secrets.token_bytes(N)
print("Random Secrets Token Bytes for Crypto:", crypto_bytes)

crypto_rand_string = secrets.token_urlsafe(N)
print("Random URL safe String for Crypto:", crypto_rand_string)

crypto_hex = secrets.token_hex(N)
print("Random Hexadecimal String for Crypto:", crypto_hex)

crypto_int_bits = secrets.randbits(N)
print("Random 18 bit Crypto Integer:",crypto_int_bits )
```

Output

```Random Secrets Token Bytes for Crypto: b'm\xf9j\xd7\xf0J\$,e\x01yz\x07V\xe4H\xa6"'
Random URL safe String for Crypto: pSizKJUs39ywa74dLCGesPU_
Apart from the random module we have `os` and `secrets` modules in Python which can also be used to generate random data. The `os`module is generally used to generate Operating System Specific Crypto Bytes code, where we can use the secrets modules to generate secure random data.