I'm wondering how to print specific items from a list e.g. given:
li = [1,2,3,4] I want to print just the 3rd and 4th within a loop and I have been trying to use some kind of for-loop like the following:
for i in range (li(3,4)): print (li[i]) However I'm Getting all kinds of error such as:
TypeError: list indices must be integers, not tuple. TypeError: list object is not callable I've been trying to change () for [] and been shuffling the words around to see if it would work but it hasn't so far.
3 Answers
Using slice notation you can get the sublist of items you want:
>>> li = [1,2,3,4] >>> li[2:] [3, 4] Then just iterate over the sublist:
>>> for item in li[2:]: ... print item ... 3 4 You should do:
for i in [2, 3]: print(li[i]) By range(n), you are getting [0, 1, 2, ..., n-1]
By range(m, n), you are getting [m, m+1, ..., n-1]
That is why you use range, getting a list of indices.
It is more recommended to use slicing like other fellows showed.
li(3,4) will try to call whatever li is with the arguments 3 and 4. As a list is not callable, this will fail. If you want to iterate over a certain list of indexes, you can just specify it like that:
for i in [2, 3]: print(li[i]) Note that indexes start at zero, so if you want to get the 3 and 4 you will need to access list indexes 2 and 3.
You can also slice the list and iterate over the lists instead. By doing li[2:4] you get a list containing the third and fourth element (i.e. indexes i with 2 <= i < 4). And then you can use the for loop to iterate over those elements:
for x in li[2:4]: print(x) Note that iterating over a list will give you the elements directly but not the indexes.
