# Python | Count occurrences of a character in string

Given a string, the task is to count the frequency of a single character in that string. This particular operation on string is quite useful in many applications such as removing duplicates or detecting unwanted characters.

Method #1 : Naive method

Iterate the entire string for that particular character and then increase the counter when we encounter the particular character.

 `# Python3 code to demonstrate  ` `# occurrence frequency using  ` `# naive method  ` ` `  `# initializing string  ` `test_str ``=` `"GeeksforGeeks"` ` `  `# using naive method to get count  ` `# counting e  ` `count ``=` `0` ` `  `for` `i ``in` `test_str: ` `    ``if` `i ``=``=` `'e'``: ` `        ``count ``=` `count ``+` `1` ` `  `# printing result  ` `print` `(``"Count of e in GeeksforGeeks is : "` `                            ``+`  `str``(count)) `

Output :

`Count of e in GeeksforGeeks is : 4`

Method #2 : Using `count()`

Using `count()` is the most conventional method in Python to get the occurrence of any element in any container. This is easy to code and remember and hence quite popular.

 `# Python3 code to demonstrate  ` `# occurrence frequency using  ` `# count() ` ` `  `# initializing string  ` `test_str ``=` `"GeeksforGeeks"` ` `  `# using count() to get count  ` `# counting e  ` `counter ``=` `test_str.count(``'e'``) ` ` `  `# printing result  ` `print` `(``"Count of e in GeeksforGeeks is : "` `                           ``+`  `str``(counter)) `

Output :

```Count of e in GeeksforGeeks is : 4
```

Method #3 : Using `collections.Counter()`

This is the lesser known method to get the occurrence of the element across any container in Python. This also performs the task similar to above two method, just is a function of a different library i.e collections.

 `# Python3 code to demonstrate  ` `# occurrence frequency using  ` `# collections.Counter() ` `from` `collections ``import` `Counter ` ` `  `# initializing string  ` `test_str ``=` `"GeeksforGeeks"` ` `  `# using collections.Counter() to get count  ` `# counting e  ` `count ``=` `Counter(test_str) ` ` `  `# printing result  ` `print` `(``"Count of e in GeeksforGeeks is : "` `                       ``+`  `str``(count[``'e'``])) `

Output :

```Count of e in GeeksforGeeks is : 4
```

Method #4 : Using lambda + `sum()` + `map()`

Lambda functions, along with `sum()` and` map()` can achieve this particular task of counting the total occurrences of particular element in a string. This uses` sum()` to sum up all the occurrences obtained using` map()`.

 `# Python3 code to demonstrate  ` `# occurrence frequency using  ` `# lambda + sum() + map() ` ` `  `# initializing string  ` `test_str ``=` `"GeeksforGeeks"` ` `  `# using lambda + sum() + map() to get count  ` `# counting e  ` `count ``=` `sum``(``map``(``lambda` `x : ``1` `if` `'e'` `in` `x ``else` `0``, test_str)) ` ` `  `# printing result  ` `print` `(``"Count of e in GeeksforGeeks is : "` `                            ``+`  `str``(count)) `

Output :

```Count of e in GeeksforGeeks is : 4
```

Method #5 : Using `re + findall()`

Regular Expressions can help us to achieve many coding tasks related to strings. They can also facilitate us in achieving the task of finding the occurrence of element in string.

 `# Python3 code to demonstrate  ` `# occurrence frequency using  ` `# re + findall() ` `import` `re ` ` `  `# initializing string  ` `test_str ``=` `"GeeksforGeeks"` ` `  `# using re + findall() to get count  ` `# counting e  ` `count ``=` `len``(re.findall(``"e"``, test_str)) ` ` `  `# printing result  ` `print` `(``"Count of e in GeeksforGeeks is : "` `                            ``+`  `str``(count)) `

Output :

```Count of e in GeeksforGeeks is : 4
```

My Personal Notes arrow_drop_up Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :

5

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.