list.index
Find the first item of the list that equals x.
Python 3.13
list.index(x[, start[, end]])- [ ]optional part
- x
- The value to search for.Any
- start
- The index to start searching from, 0 by default; a negative one counts from the end.intOptional
- end
- The index before which the search stops, the end by default; a negative one counts from the end.intOptional
Return value
The index of the first matching item; raises ValueError if there is none.
Examples
Position of an item in a list
Python 3.13
print([1, 2, 3].index(2))1
Searching from a given position
Python 3.13
a = ['a', 'b', 'a']
print(a.index('a', 1))2
Details
If the item may be missing, check for it first: x in a.