In this tutorial, we will look at how to check if a set contains an element or not in Python with the help of some examples.
How to check if an element is in a set?

You can use the membership operator in
to check if a set contains an element or not in Python. The following is the syntax:
# check if element e is in set a e in a
It returns a boolean value. True
if the element is present in the set and False
if it isn’t.
Let’s look at an example –
# create a set a = {1, 2, 3} # check if 3 is in a print(3 in a)
Output:
True
Here we check whether the element 3
is in the set a or not. We get True as the output because the set a
, here, contains the element 3
.
Let’s look at another example.
# create a set a = {1, 2, 3} # check if 4 is in a print(4 in a)
Output:
False
Here we get False
as the output because the set a
does not contain the element 4
.
Alternatively, you can also use the set issubset() function to check whether a set contains an element or not. The idea is to check whether the set contains a subset with the element we want to check for. Here’s an example.
# create a set a = {1, 2, 3} # check if 3 is in a print({3}.issubset(a)) # check if 4 is in a print({4}.issubset(a))
Output:
True False
We get the correct result.
Note that you should prefer the membership operator in
to using the issubset() function for checking whether a set contains an element or not as it is simple and intuitive.
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