Python From X Import Y - ashish9342/FreeCodeCamp GitHub Wiki
If you have read the import statements
wiki then you'd have seen me use this statement in one of the examples. Today, we'll try to understand what it does
So picking up the same example:
>>> from math import ceil, sqrt
>>> # here it would be
>>> sqrt(36)
<<< 6
🚀 Run Code
Or we could use this:
>>> import math
>>> # here it would be
>>> math.sqrt(36)
<<< 6
🚀 Run Code
Then our code would look likemath.sqrt(x)
instead of sqrt(x)
. This happens because when we use import x
, a namespace x
is itself created to avoid name conflicts. You have to access every single object of the module as x.<name>
. But when we use from x import y
we agree to add y
to the main global namespace. So while using this we have to make sure that we don't have an object with same name in our program.
Never use
from x import y
if an object namedy
already exists
For example, in os
module there's a method open
. But we even have a built-in function called open
. So, here we should avoid using from os import open
.
We can even use form x import *
, this would import all the methods, classes of that module to the global namespace of the program. This is a bad programming practice. Please avoid it.