Generate random integers within a range in Python

# Generate random integers within a range in Python

David Y.

Using Python, how do I get a random integer within a particular range, for example, between 0 and 9?

## The Solution

If we’re using randomness for a non-security purpose, such as modeling a system or building a game, we can generate pseudorandom numbers with the built-in Python `random` module. This module provides two different functions that will serve our purpose, `randrange` and `randint`. Consider the following code:

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```.css-3i4pd0{position:relative;color:inherit;-webkit-transition:box-shadow 0.3s;transition:box-shadow 0.3s;will-change:box-shadow;outline:0;display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;z-index:9;}.css-3i4pd0:hover,.css-3i4pd0:focus{cursor:pointer;}.css-3i4pd0:hover .e1fliqfg1,.css-3i4pd0:focus .e1fliqfg1{fill:#e1567c;cursor:pointer;}import random

random_one = random.randrange(0,9) # will produce one of [0,1,2,3,4,5,6,7,8]
random_two = random.randint(0,9) # will produce one of [0,1,2,3,4,5,6,7,8,9]
```

The `randrange` function will produce an integer between the first and second arguments, exclusive of the second. The `randint` function will produce an integer inclusive of the second argument. Behind the scenes, `randint` is merely an alias for `randrange(start, stop+1)`.

The `randrange` function can also take a `step` argument, allowing us to skip elements of the provided range. For example, if we wanted to select any even number between 0 and 9, we could use a `step` of 2, as below:

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```import random

random_even = random.randrange(0,9,2) # will produce one of [0,2,4,6,8]
```

As noted in a warning near the top of the `random` module’s documentation, values produced by its generators should not be used for security purposes. For that, we’ll need the `secrets` module, which provides a `randbelow` method we can use to generate a random integer between 0 and the provided argument, exclusive.

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```import secrets

secure_random = secrets.randbelow(10) # will produce one of [0,1,2,3,4,5,6,7,8,9]
```

Should we want a random number with a higher starting point than 0, as is possible with `randrange`, we can add our starting point to the result, as below:

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```import secrets

secure_random = 1 + secrets.randbelow(10) # will produce one of [1,2,3,4,5,6,7,8,9,10]
```
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