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# Python | Count occurrences of an element in a list

Given a list in Python and a number x, count the number of occurrences of x in the given list.

Examples:

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

Input: lst = [8, 6, 8, 10, 8, 20, 10, 8, 8], x = 16
Output: 0
Explanation: 16 appears zero times in given list.```

## Method 1: Count occurrences of an element in a list Using a Loop in Python

We keep a counter that keeps on increasing if the required element is found in the list.

## Python3

 `# 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`

Time complexity: O(n)
Auxiliary space: O(1)

### Method 2: Count occurrences of an element in a list Using count()

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

## Python3

 `# Python code to count the number of occurrences``def` `countX(lst, x):``    ``return` `lst.count(x)`  `# 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`

Time Complexity: O(n)
Auxiliary Space: O(n), where n is number of elements in list.

## Method 3: Count occurrences of an element in a list Using Counter()

The counter method returns a dictionary with occurrences of all elements as a key-value pair, where the key is the element and the value is the number of times that element has occurred.

## Python3

 `from` `collections ``import` `Counter` `# declaring the list``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`

## Method 4: Count occurrences of an element in a list Using countof()

Operator.countOf() is used for counting the number of occurrences of b in a. It counts the number of occurrences of value. It returns the Count of a number of occurrences of value.

## Python3

 `import` `operator as op` `# declaring the list``l ``=` `[``1``, ``1``, ``2``, ``2``, ``2``, ``3``, ``3``, ``4``, ``4``, ``5``, ``5``]` `# driver program``x ``=` `2``print``(f``"{x} has occurred {op.countOf(l, x)} times"``)`

Output

`2 has occurred 3 times`

## Method 5: Count occurrences of an element in a list Using dictionary comprehension

Python allows dictionary comprehensions. We can create dictionaries using simple expressions. A dictionary comprehension takes the form {key: value for (key, value) in iterable}

## Python3

 `lis ``=` `[``'a'``, ``'d'``, ``'d'``, ``'c'``, ``'a'``, ``'b'``, ``'b'``, ``'a'``, ``'c'``, ``'d'``, ``'e'``]``occurrence ``=` `{item: lis.count(item) ``for` `item ``in` `lis}``print``(occurrence.get(``'e'``))`

Output

`1`

## Method 6: Count occurrences of an element in a list Using the panda’s library

Pandas Series.value_counts() function return a Series containing counts of unique values. The resulting object will be in descending order so that the first element is the most frequently-occurring element.

## Python3

 `import` `pandas as pd` `# declaring the list``l ``=` `[``1``, ``1``, ``2``, ``2``, ``2``, ``3``, ``3``, ``4``, ``4``, ``5``, ``5``]` `count ``=` `pd.Series(l).value_counts()``print``(``"Element Count"``)``print``(count)`

Output:

```Element    Count
2            3
1            2
3            2
4            2
5            2
dtype: int64```

## Python3

 `l ``=` `[``1``, ``1``, ``2``, ``2``, ``2``, ``3``, ``3``, ``4``, ``4``, ``5``, ``5``]``ele``=``1``x``=``[i ``for` `i ``in` `l ``if` `i``=``=``ele]``print``(``"the element"``,ele,``"occurs"``,``len``(x),``"times"``)`

Output

`the element 1 occurs 2 times`

Method: Using enumerate function

## Python3

 `l ``=` `[``1``, ``1``, ``2``, ``2``, ``2``, ``3``, ``3``, ``4``, ``4``, ``5``, ``5``]``ele``=``1``x``=``[i ``for` `j,i ``in` `enumerate``(l) ``if` `i``=``=``ele]``print``(``"the element"``,ele,``"occurs"``,``len``(x),``"times"``)`

Output

`the element 1 occurs 2 times`

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