CODEWITHSUNDEEP
pythonpython-3.xlist
Slania87
Slania87

Reputation: 17

How to iterate over a python list?

If I execute this code, the following error message occurs:

IndexError: list index out of range python

def reverse_invert(lst):
    inverse_list = []

    for i in lst:
        if isinstance( i, int ):
             inverse_list.append(lst[i])
        #print(inverse_list)       
             print(i)       
        else:
            break
    return inverse_list

Why is it?

Upvotes: 1

Views: 1183

Answers (4)

Uriel
Uriel

Reputation: 16174

for i in lst:

will iterate the elements of lst.

If you want to iterate indexes, use

for i in range(len(lst)):

If you want both the element and the index, use enumerate:

for i, el in enumerate(lst):

Upvotes: 1

jahmed31
jahmed31

Reputation: 3766

Generally it means that you are providing an index for which a list element does not exist.

E.g, if your list was

[1, 3, 5, 7], and you asked for the element at index 10, you would be well out of bounds and receive an error, as only elements 0 through 3 exist.

Upvotes: 0

zipa
zipa

Reputation: 27869

List comprehension would work fine:

a = [1, 'a', 2, 3]

print [d for d in a[::-1] if isinstance(d, int)]

And if you want to reverse it just tiny change would do:

a = [1, 'a', 2, 3]

print [d for d in a[::-1] if isinstance(d, int)]

Or maybe I missed your point.

Upvotes: 0

Hasan Alper Ocalan
Hasan Alper Ocalan

Reputation: 318

You are iterating the elements of list but trying to use the element as index. You should change your code like this:

def reverse_invert(lst):
inverse_list = []

for i in lst:
    if isinstance( i, int ):
         inverse_list.append(i) # changed this one.
    #print(inverse_list)       
         print(i)       
    else:
        break
return inverse_list

Upvotes: 0

Related Questions