How to Avoid IndexError When Populating an Empty Python List?

Fixing IndexError when Assigning Elements to a List

When attempting to create a list by assigning each element in turn, you may encounter an IndexError if the target list is initially empty. This error arises because you are trying to access an index that doesn't exist within the list.

To resolve this issue and correctly add elements to the list, you can use the append method:

for l in i:
    j.append(l)

This approach will add each element l to the end of the list j, without causing an IndexError.

Alternatively, if you want to use the Python list like an array in other languages, you can first create a list with the appropriate number of elements set to None. Then, you can overwrite the values in specific positions:

j = [None] * len(i)
#j == [None, None, None, None, None, None]

for l in i:
    j[k] = l
    k += 1

Remember, a Python list does not allow you to assign a value to an index that doesn't exist, which is why the initial None values are necessary in this case.

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