# Modules

{% embed url="<https://youtu.be/MyT85D8UdD0>" %}

&#x20;[Modules](http://python.swaroopch.com/modules.html)

Modules are very useful to use in our programs. They are pieces of code that someone else wrote (they could even be your own modules) that you can import into your program. They have functions on them that you can call to perform something special.

## Examples

Some common modules are `sys`, `os`, `math` and `random`. These are really handy and one of my favorites is `random`. We could create a little dice rolling program using `random`:

```python
import random
print(random.randint(1,6))
```

This very simple program will print out a random number between 1 and 6.

You can import modules in various ways:

* `import random` will simply import all of random's functions prefixed by

  random as we saw in the example above.  -&#x20;
* `import random as rand` will allow you to shorten the command like:&#x20;

  `print(rand.randint(1,6))`
* `from random import randint` will allow you to call `randint` without any

  prefix: `print(randint(1,6))`
* `from random import *` will import all of randoms methods in a manner that you

  don't have to prefix them (I don't recommend doing this)