Importing elements from another Python module makes them available in the current context (usually a script or a REPL-session).
This allows for code to be split into several segments to keep them invididually self-contained, reusable and maintainable.
Use case
Make a separate module or elements of a module available in the current context.
Example: Importing a whole Module
In the following example, we import the math-module from _Python_s standard library and access the sin(…)-function and pi therein.
import math
print(math.sin(math.pi))
Example: Importing Elements from a Module
In this example, only the sin(…)-function and pi will be imported and used.
from math import sin, pi
print(sin(pi))