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Python Python Collections (2016, retired 2019) Lists Shopping List Take Three

Aditya Pandey
Aditya Pandey
7,210 Points
Posted by Aditya Pandey
Aditya Pandey
7,210 Points

What does 'is' do?

I don't understand what the 'is' keyword is used for. Can anyone clarify?

1 Answer

James Morris
James Morris
5,104 Points

Hi Aditya,

the "is" keyword compares one value to another and tells you whether the statement is true or not. so for example you can run the code below and both print statements return "True"

a = 1
b = 1
print(a is b)
print(a == b)

Try it out in workspaces.

Best of luck!

Leeland Miller
Leeland Miller
1,324 Points
Leeland Miller
Leeland Miller
1,324 Points

You have to be careful with using is though. is tests for identity, not equality. What that means is it is looking to see if the two values are in the same place in memory.

For example

list_one = [1, 2, 3]
list_two = [1, 2, 3]

print(list_one == list_two) # Prints True
print(list_one is list_two) # Prints False