Given a matrix, extract row numbers with particular string occurrence.

Input: test_list = [[“GFG”, “best”, “geeks”], [“geeks”, “rock”], [“GFG”, “for”, “CS”], [“Keep”, “learning”]], K = “GFG”Output: [0, 2]Explanation: 0th index and 2nd index have “GFG” in them as element.

Input: test_list = [[“GFG”, “best”, “geeks”], [“geeks”, “rock”, “GFG”], [“GFG”, “for”, “CS”], [“Keep”, “learning”]], K = “GFG”Output: [0, 1, 2]Explanation: 0th index, 1st index and 2nd index have “GFG” in them as element.

**Method #1 : Using loop**

In this, we iterate for each element in Matrix and get the indices of all the rows which match the K string.

## Python3

`# Python3 code to demonstrate working of` `# Rows with K string in Matrix` `# Using loop` ` ` `# initializing list` `test_list ` `=` `[[` `"GFG"` `, ` `"best"` `, ` `"geeks"` `], [` `"geeks"` `, ` `"rock"` `],` ` ` `[` `"GFG"` `, ` `"for"` `, ` `"CS"` `], [` `"Keep"` `, ` `"learning"` `]]` ` ` `# printing original list` `print` `(` `"The original list is : "` `, test_list)` ` ` `# initializing K` `K ` `=` `"GFG"` ` ` `res ` `=` `[]` ` ` `# enumerate() used for getting both index and ele` `for` `idx, ele ` `in` `enumerate` `(test_list):` ` ` ` ` `# checking for K String` ` ` `if` `K ` `in` `ele:` ` ` `res.append(idx)` ` ` `# printing result` `print` `(` `"Rows with K : "` `+` `str` `(res))` |

**Output:**

The original list is : [[‘GFG’, ‘best’, ‘geeks’], [‘geeks’, ‘rock’], [‘GFG’, ‘for’, ‘CS’], [‘Keep’, ‘learning’]]

Rows with K : [0, 2]

**Method #2 : Using list comprehension**

This is similar to above method, difference being its a shorthand to solve problem.

## Python3

`# Python3 code to demonstrate working of` `# Rows with K string in Matrix` `# Using list comprehension` ` ` `# initializing list` `test_list ` `=` `[[` `"GFG"` `, ` `"best"` `, ` `"geeks"` `], [` `"geeks"` `, ` `"rock"` `],` ` ` `[` `"GFG"` `, ` `"for"` `, ` `"CS"` `], [` `"Keep"` `, ` `"learning"` `]]` ` ` `# printing original list` `print` `(` `"The original list is : "` `, test_list)` ` ` `# initializing K` `K ` `=` `"GFG"` ` ` `# shorthand to get result` `res ` `=` `[idx ` `for` `idx, ele ` `in` `enumerate` `(test_list) ` `if` `K ` `in` `ele]` ` ` `# printing result` `print` `(` `"Rows with K : "` `+` `str` `(res))` |

**Output:**

The original list is : [[‘GFG’, ‘best’, ‘geeks’], [‘geeks’, ‘rock’], [‘GFG’, ‘for’, ‘CS’], [‘Keep’, ‘learning’]]

Rows with K : [0, 2]

Attention geek! Strengthen your foundations with the **Python Programming Foundation** Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the **Python DS** Course. And to begin with your Machine Learning Journey, join the **Machine Learning – Basic Level Course**