Lambda and filter in Python Examples

Prerequisite : Lambda in Python

Given a list of numbers, find all numbers divisible by 13.

```Input : my_list = [12, 65, 54, 39, 102,
339, 221, 50, 70]
Output : [65, 39, 221]
```

We can use Lambda function inside the filter() built-in function to find all the numbers divisible by 13 in the list. In Python, anonymous function means that a function is without a name.

The filter() function in Python takes in a function and a list as arguments. This offers an elegant way to filter out all the elements of a sequence “sequence”, for which the function returns True.

 `# Python Program to find numbers divisible  ` `# by thirteen from a list using anonymous  ` `# function ` ` `  `# Take a list of numbers.  ` `my_list ``=` `[``12``, ``65``, ``54``, ``39``, ``102``, ``339``, ``221``, ``50``, ``70``, ] ` ` `  `# use anonymous function to filter and comparing  ` `# if divisible or not ` `result ``=` `list``(``filter``(``lambda` `x: (x ``%` `13` `=``=` `0``), my_list))  ` ` `  `# printing the result ` `print``(result)  `

Output:

```[65, 39, 221]
```

Given a list of strings, find all palindromes.

 `# Python Program to find palindromes in  ` `# a list of strings. ` ` `  `my_list ``=` `[``"geeks"``, ``"geeg"``, ``"keek"``, ``"practice"``, ``"aa"``] ` ` `  `# use anonymous function to filter palindromes. ` `# Please refer below article for details of reversed ` `# https://www.geeksforgeeks.org/reverse-string-python-5-different-ways/ ` `result ``=` `list``(``filter``(``lambda` `x: (x ``=``=` `"".join(``reversed``(x))), my_list))  ` ` `  `# printing the result ` `print``(result)  `

Output :

```['geeg', 'keek', 'aa']
```

Given a list of strings and a string str, print all anagrams of str

 `# Python Program to find all anagrams of str in  ` `# a list of strings. ` `from` `collections ``import` `Counter ` ` `  `my_list ``=` `[``"geeks"``, ``"geeg"``, ``"keegs"``, ``"practice"``, ``"aa"``] ` `str` `=` `"eegsk"` ` `  `# use anonymous function to filter anagrams of x. ` `# Please refer below article for details of reversed ` `# https://www.geeksforgeeks.org/anagram-checking-python-collections-counter/ ` `result ``=` `list``(``filter``(``lambda` `x: (Counter(``str``) ``=``=` `Counter(x)), my_list))  ` ` `  `# printing the result ` `print``(result)  `

Output :

```['geeks', 'keegs']
```

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