# Python | Counting occurrences of an item in a list

Counters | Python Methods and Functions

Examples:

` Input: lst = [15, 6, 7, 10, 12, 20, 10, 28, 10] x = 10 Output: 3 10 appears three times in given list. Input: lst = [8, 6, 8, 10, 8, 20, 10, 8, 8] x = 16 Output: 0 `

Method 1 (Simple Approach)

 ` # Python code to count the number of occurrences ` ` def ` ` countX (lst, x): ` ` ` ` count ` ` = ` ` 0 ` ` for ` ` ele ` ` in ` ` lst: ` ` if ` ` (ele ` ` = ` ` = ` ` x): ` ` count ` ` = ` ` count ` ` + ` ` 1 ` ` return ` ` count `   ` Driver code ` ` lst ` ` = ` ` [` ` 8 ` `, ` ` 6 ` `, ` ` 8 ` `, ` ` 10 ` `, ` ` 8 ` `, ` ` 20 ` `, ` ` 10 ` `, ` ` 8 ` `, ` ` 8 ` ] ` x ` ` = ` ` 8 ` ` print ` ` (` `' { } has occurred {} times' ` `. ` ` format ` ` (x, countX ( lst, x))) `

` Output: 8 has occurred 5 times `

Method 2 (Using count ())
The idea is to use list () method to count the number of occurrences.

 ` # Python code to count the number of occurrences ` ` def ` ` countX (lst, x): ` ` ` ` return ` lst.count (x)   ` Code driver ` ` lst ` ` = ` ` [` ` 8 ` `, ` ` 6 ` `, ` ` 8 ` `, ` ` 10 ` ` , ` ` 8 ` `, ` ` 20 ` `, ` ` 10 ` `, ` ` 8 ` `, ` ` 8 ` `] ` ` x ` ` = ` ` 8 ` ` print ` ` (` ` '{} has occurred {} times' ` `. ` format ` (x, countX (lst, x))) `

` Output: 8 has occurred 5 times `

Method 2 (using counter ())
The Counter method returns a dictionary with entries of all elements as a key-value pair, where key — it is an element, and value — the number of times this element has been encountered.

 ` from ` ` collections ` ` import ` ` Counter ` ` `  ` # list declaration ` ` l ` ` = ` ` [` ` 1 ` `, ` ` 1 ` `, ` ` 2 ` `, ` ` 2 ` `, ` ` 3 ` `, ` ` 3 ` `, ` ` 4 ` `, ` ` 4 ` `, ` ` 5 ` `, ` ` 5 ` `] ` ` `  ` # driver program ` ` x ` ` = ` ` 3 ` ` d ` ` = ` ` Counter (l) ` ` print ` ` (` ` '{} has occurred {} times' ` `. ` ` format ` ` (x, d [x])) `

` Output: 3 has occurred 2 times `