In Python, a file containing statements and definitions is referred as a module.

All the methods and variables defined in a Python module can be imported and accessed from another modules.

Let us create a module for performing the `math.py`

.

```
# Python Module example
def add(a, b):
return a + b
def subtract(a, b):
return a - b
def multiply(a, b):
return a * b
```

Here, we have defined three functions inside the `math`

module.

## How to Import a Module in Python?

To import a module you need to use `import`

statement

```
import math
sum = math.add(5, 10)
print("Sum is:", sum)
sum = math.subtract(15, 10)
print("Sub is:", sum)
```

**Output:**

```
Sum is: 15
Sub is: 5
```

You can also import the module by renaming as follows:

```
import math as m
sum = m.add(5, 10)
print("Sum is:", sum)
sum = m.subtract(15, 10)
print("Sub is:", sum)
```

Notice that in the above example, we have imported the entire module. Let's say you only wanted a specific function inside the module. We can do that too, like so:

```
from math import add
from math import subtract
sum = add(5, 10)
print("Sum is:", sum)
sub = subtract(15, 10)
print("Sub is:", sub)
```

## Python Built-in Modules

Python has many built-in modules, and we've already used one extensively in this class, namely the `math`

module.

Here are some other popular useful built-in modules that might be familiar to you:

array | copy | html | http |

fileinput | io | json | |

gc | gzip | ipaddress | numbers |

pip | pipes | random | ssl |

string | symbol | sys | time |

Definitely check out the documentation for these modules if you're curious about what functionality any of them offer!