as alias

Learn to alias with import x as y.

The as alias

The as keyword gives a module a short name (alias). This is used to shorten long module names:

import math as m
print(m.sqrt(16))  # 4.0
print(m.pi)        # 3.14159...

Here the math module is loaded under the name m. Now m.sqrt and m.pi are used. The name math is not available.

This is a common technique to write shorter code.

Common aliases

The Python community has established short names for some modules. These names are used the same way across all projects:

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

These three shortcuts are standard in the data science world. np, pd and plt are recognised by everyone. Inconsistent aliases make code unreadable.

When choosing your own aliases, keep them short but meaningful.

Exercise Square root with import math as m

Write import math as m. Then write print(m.sqrt(16)).

Show example solution

import math as m
print(m.sqrt(16))

Test yourself

Match as aliases

import math as m

math → m
m.sqrt(16)

Call with short name
as

Alias keyword
math (now gone)

Not available
After import math as m, what does math.sqrt(16) do?
- Works
- Raises NameError
- Does not run but no error
- Raises ImportError
Show answer

Raises NameError — With as m the name math becomes m; math is no longer defined.

Complete the as keyword

import math ____ m
print(m.sqrt(16))

Show answer

import math as m
print(m.sqrt(16))

Next lesson: __name__ == '__main__'

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies