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Access the sole element of a set

Tags:

python

set

People also ask

How do you access the elements of a set?

You can't access set elements by index. You have to access the elements using an iterator. set<int> myset; myset. insert(100); int setint = *myset.

How do you access individual elements of a set in Python?

You cannot access items in a set by referring to an index or a key. But you can loop through the set items using a for loop, or ask if a specified value is present in a set, by using the in keyword.

How do you print the first element of a set in Python?

We can access the first item in the set by using iter() function, we have to apply next() to it to get the first element.

Can you index a set in Python?

There is no index attached to any element in a python set. So they do not support any indexing or slicing operation.


Use set.pop:

>>> {1}.pop()
1
>>>

In your case, it would be:

return S.pop()

Note however that this will remove the item from the set. If this is undesirable, you can use min|max:

return min(S) # 'max' would also work here

Demo:

>>> S = {1}
>>> min(S)
1
>>> S
set([1])
>>> max(S)
1
>>> S
set([1])
>>> 

I would use:

e = next(iter(S))

This is non-destructive and works even when there is more than one element in the set. Even better, it has an option to supply a default value e = next(iter(S), default).

You could also use unpacking:

[e] = S

The unpacking technique is likely to be the fastest way and it includes error checking to make sure the set has only one member. The downside is that it looks weird.


Sorry, late to the party. To access an element from a set you can always cast the set into a list and then you can use indexing to return the value you want.

In the case of your example:

return list(S)[0]

One way is: value=min(set(['a','b','c')) produces 'a'. Obviously you can use max instead.


You can assign the last element to a variable, using star operation.

>>> a={"fatih"}
>>> b=str(*a)
>>> b
'fatih'

Now the varible b have a string object.

If the sole elemant is a number, you could use int():

>>> a={1}
>>> c=int(*a)
>>> c
1