Add items to List While Iterating Python (original) (raw)
Last Updated : 27 Nov, 2024
Python has many ways to append to a list while iterating. List comprehension is a compact and efficient way to append elements while iterating. We can use it to build a new list from an existing one or generate new values based on a condition.
Python `
a = [1, 2, 3]
a += [i + 4 for i in range(3)] print(a)
`
Other ways to append to a list while iterating are:
Table of Content
Using extend() Method
If we want to append multiple items to a list at once, we can use the extend() method. This method adds all elements from another list to the original list.
Python `
a = [1, 2, 3] a.extend([4, 5, 6]) print(a)
`
Using a While Loop
Sometimes, a while loop might be useful for appending to a list. You can manually control the loop’s conditions.
Python `
a = [1, 2, 3] i = 0 while i < 3: a.append(i + 4) i += 1 print(a)
`
Using map() Function
The map() function applies a function to all items in an iterable. This method can also be used to append items while iterating.
Python `
a = [1, 2, 3] a += list(map(lambda x: x + 4, range(3))) print(a)
`
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