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+--- Thread: TypeError indexing a range of elements directly on the list (/thread-25441.html)
TypeError indexing a range of elements directly on the list - JFerreira - Mar-30-2020
Hi,
I am getting an TypeError, and not sure why? My goal is to write on the second and third position of a list . I can do it using a for loop but I would like to avoid the for loop by indexing a range of elements directly on the list. How can I do it?
>>>list=[1,3,4,30,10,20]
>>>for i in range(1,3,1):
list[i] = 0
>>>list
[1, 0, 0, 30, 10, 20]
>>>list[1:3] = 1
Traceback (most recent call last):
File "<input>", line 1, in <module>
TypeError: can only assign an iterable
RE: TypeError indexing a range of elements directly on the list - stullis - Mar-30-2020
Hmm, I never thought to even try that. The problem is that list[1:3] selects values from index 1 up to index 3 for a total of 2 items. You cannot replace multiple items with a single item. Instead, you need to provide an interable for the interpreter to loop over and replace values.
list[1:3] = [1]While we're at it, it's inadvisable to use "list" as a variable name. Think of it like a reserved keyword because there's a builtin function called list() and Python replaces it with the variable.
RE: TypeError indexing a range of elements directly on the list - bowlofred - Mar-30-2020
If you want to replace both items with "1",s then something like this:
>>> l = [1,3,4,30,10,20] >>> l [1, 3, 4, 30, 10, 20] >>> l[1:3] = [1] * 2 >>> l [1, 1, 1, 30, 10, 20]