[Tut] Python List Methods

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Python List Methods

The most important collection data type in Python is the

Code:

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:



Method |
Description

Code:

lst.append(x)

|
Appends element

Code:

x

to the list

Code:

lst

.

Code:

lst.clear()

|
Removes all elements from the list

Code:

lst

–which becomes empty.

Code:

lst.copy()

|
Returns a copy of the list

Code:

lst

. Copies only the list, not the elements in the list (shallow copy).

Code:

lst.count(x)

|
Counts the number of occurrences of element

Code:

x

in the list

Code:

lst

.

Code:

lst.extend(iter)

|
Adds all elements of an iterable

Code:

iter

(e.g. another list) to the list

Code:

lst

.

Code:

lst.index(x)

|
Returns the position (index) of the first occurrence of value

Code:

x

in the list

Code:

lst

.

Code:

lst.insert(i, x)

|
Inserts element

Code:

x

at position (index)

Code:

i

in the list

Code:

lst

.

Code:

lst.pop()

|
Removes and returns the final element of the list

Code:

lst

.

Code:

lst.remove(x)

|
Removes and returns the first occurrence of element

Code:

x

in the list

Code:

lst

.

Code:

lst.reverse()

|
Reverses the order of elements in the list

Code:

lst

.

Code:

lst.sort()

|
Sorts the elements in the list

Code:

lst

in ascending order.

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:

Code:

>>> 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]

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