Python List Methods

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The most important collection data type in Python is the list data type. You’ll use lists basically in all your future projects so take 3-5 minutes and study this short guide carefully.

You can also play my short video tutorial as you read over the methods:

Python List Methods
MethodDescription
lst.append(x)Appends element x to the list lst.
lst.clear()Removes all elements from the list lst--which becomes empty.
lst.copy()Returns a copy of the list lst. Copies only the list, not the elements in the list (shallow copy).
lst.count(x)Counts the number of occurrences of element x in the list lst.
lst.extend(iter)Adds all elements of an iterable iter(e.g. another list) to the list lst.
lst.index(x)Returns the position (index) of the first occurrence of value x in the list lst.
lst.insert(i, x)Inserts element x at position (index) i in the list lst.
lst.pop()Removes and returns the final element of the list lst.
lst.remove(x)Removes and returns the first occurrence of element x in the list lst.
lst.reverse()Reverses the order of elements in the list lst.
lst.sort()Sorts the elements in the list lst in ascending order.

Let’s dive into a couple of examples:

l = []

l.append(2)
print(l)

l.clear()
print(l)

l.append(2)
print(l)

print(l.copy())

print(l.count(2))

l.extend([2,3,4])
print(l)

print(l.index(3))

l.insert(2, 99)
print(l)

print(l.pop())

l.remove(2)
print(l)

l.reverse()
print(l)

l.sort()
print(l)

Puzzle: Can you figure out all outputs of this interactive Python script?

Before you read on, first figure out the outputs. Then, compare them with the results here:

[2]
[]
[2]
[2]
1
[2, 2, 3, 4]
2
[2, 2, 99, 3, 4]
4
[2, 99, 3]
[3, 99, 2]
[2, 3, 99]

If you’ve studied the table carefully, you’ll know the most important list methods in Python. Let’s have a look at some examples of above methods:

>>> l = []
>>> l.append(2)
>>> l
[2]
>>> l.clear()
>>> l
[]
>>> l.append(2)
>>> l
[2]
>>> l.copy()
[2]
>>> l.count(2)
1
>>> l.extend([2,3,4])
>>> l
[2, 2, 3, 4]
>>> l.index(3)
2
>>> l.insert(2, 99)
>>> l
[2, 2, 99, 3, 4]
>>> l.pop()
4
>>> l.remove(2)
>>> l
[2, 99, 3]
>>> l.reverse()
>>> l
[3, 99, 2]
>>> l.sort()
>>> l
[2, 3, 99]

Action Steps:

Here’s your free PDF cheat sheet showing you all Python list methods on one simple page. Click the image to download the high-resolution PDF file, print it, and post it to your office wall: