List Methods

We have discussed methods like append(), clear(), extend(), insert(), pop(), remove() before. Now we will learn about some more list methods:

 

sort(): This method sorts the list in ascending order.

Example 1:

colors = ["voilet", "indigo", "blue", "green"]
colors.sort()
print(colors)

num = [4,2,5,3,6,1,2,1,2,8,9,7]
num.sort()
print(num)

Output:

['blue', 'green', 'indigo', 'voilet']
[1, 1, 2, 2, 2, 3, 4, 5, 6, 7, 8, 9]

 

What if you want to print the list in descending order?

We must give reverse=True as a parameter in the sort method.

Example:

colors = ["voilet", "indigo", "blue", "green"]
colors.sort(reverse=True)
print(colors)

num = [4,2,5,3,6,1,2,1,2,8,9,7]
num.sort(reverse=True)
print(num)

Output:

['voilet', 'indigo', 'green', 'blue']
[9, 8, 7, 6, 5, 4, 3, 2, 2, 2, 1, 1]

 

The reverse parameter is set to False by default.

Note: Do not mistake the reverse parameter with the reverse method.

 

reverse(): This method reverses the order of the list. 

Example:

colors = ["voilet", "indigo", "blue", "green"]
colors.reverse()
print(colors)

num = [4,2,5,3,6,1,2,1,2,8,9,7]
num.reverse()
print(num)

Output:

['green', 'blue', 'indigo', 'voilet']
[7, 9, 8, 2, 1, 2, 1, 6, 3, 5, 2, 4]

 

index(): This method returns the index of the first occurrence of the list item.

Example:

colors = ["voilet", "green", "indigo", "blue", "green"]
print(colors.index("green"))

num = [4,2,5,3,6,1,2,1,3,2,8,9,7]
print(num.index(3))

Output:

1
3

 

count(): Returns the count of the number of items with the given value.

Example:

colors = ["voilet", "green", "indigo", "blue", "green"]
print(colors.count("green"))

num = [4,2,5,3,6,1,2,1,3,2,8,9,7]

Output:

2
3

 

copy(): Returns copy of the list. This can be done to perform operations on the list without modifying the original list. 

Example:

colors = ["voilet", "green", "indigo", "blue"]
newlist = colors.copy()
print(colors)
print(newlist)

Output:

['voilet', 'green', 'indigo', 'blue']
['voilet', 'green', 'indigo', 'blue']