from import
- Python course
- Beginner
- Lesson 107/116
- 4 min
Learn selective imports with from x import y.
from import
from ... import takes only a specific item from a module. That item can now be used without the module name:
from math import sqrt
print(sqrt(16)) # 4.0Here only sqrt is taken; there is no need to write math.sqrt. But since the math name is not loaded, math.pi is not available.
This is handy for calling a few frequently used items by short names.
Advantage and risk of from import
from math import sqrt shortens code. But from math import * loads everything — this is dangerous because it can cause name clashes:
# risky
from math import *
# where did sqrt come from? log?Star imports hide which name comes from which module. They should be avoided in large projects. Instead, importing only the needed items by name is safer.
Good style: from math import sqrt, pi.
Practice from math import sqrt and pi
Write from math import sqrt, pi. Then write print(sqrt(16), pi).
Starter code
# take sqrt and pi from the math module
# print both togetherSample solution
from math import sqrt, pi
print(sqrt(16), pi)Expected output
4.0 3.141592653589793
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Complete the from import pattern
from math ____ sqrt
print(sqrt(16))from math import sqrt
print(sqrt(16))Explanation: from math import sqrt takes only sqrt.
2 Match from import
| Term | Meaning |
|---|---|
from math import sqrt |
Takes one item |
sqrt(16) |
Direct call |
import * |
Dangerous |
from math import pi, sqrt |
Multiple items |
3 After from math import sqrt, what does math.sqrt(16) do?
- Raises NameError Correct answer
- Works
- Raises TypeError
- Raises ImportError
Explanation: from math import sqrt takes only sqrt; the name math is not loaded.