Python Modules 🗂️

According to the Python Docs, a python Module is a file containing python definitions and statements, that can be later imported and used when necessary. As python users, we can use existing modules or create new modules.

Python delivers some modules and built-in functions by itself python standard library, like math or sys.

Modules have entities that can be: functions, variables, constants, classes, and objects. Every module has a name and we need to import it before use it.

Example: math is a module name and cos() is an entity inside the math module.

Some ways to import modules and their differences:

import math
Here, you import the entire module to your code and can use all its entities. The interesting thing about it is something called namespace. Namespace means that you can have your own entities named the same names as the module entities, and they don’t cause naming issues. That’s because the module is accesible in your code, but don’t enter it’s namespace. Check the example below:
```
 import math
 x = 75
 cos = math.cos(x)
 print(cos) 
```
In this example I have a variable called cos and I’m also using the math entity called cos(), and they don’t affect each other. In order to access the entity I have to use the qualification first, followed by a dot and the entity name math.cos().
from math import pi
In this case only the entity pi is being imported from math. I can access the entity without the qualification print(pi) and it will be the only thing accessible for me from the math module. If I have a variable in my code with the same name pi, depending on where I’m importing th module, it can be overrided by it or not. So it can cause some naming issues.
from math import *
This will import all entities in the math module and they can be accessed without the qualification (math.). It can also cause name conflicts, as the previous example.
from math import pi as p
In this case, we are using an alias for the entity, that can now be accessed by the alias print(p). It helps avoiding the name issues, in case we have a variable in the code named pi.

This is the basic about python modules. I hope it helps you the same way as it helped me 🐱

You can check some basic code examples about this subject here and try it yourself.

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Tags: Python. Code. Data.