# Python Program to test whether the length of rows are in increasing order

• Last Updated : 22 Jul, 2022

Given a Matrix, the following program is used to test if length all rows of a matrix are in increasing order or not. If yes, it returns True, otherwise False.

Input : test_list = [, [1, 7], [10, 2, 4], [8, 6, 5, 1, 4]]
Output : True
Explanation : 1 < 2 < 3 < 5, increasing lengths of rows, hence True.
Input : test_list = [, [1, 7], , [8, 6, 5, 1, 4]]
Output : False
Explanation : 1 <2 >1 < 5, Non-increasing lengths of rows, hence False.

Method 1 : Using loop and len()

In this, we are using loop to check whether the length of next row is greater than the present row, if not, result is flagged off.

## Python3

 `# initializing list``test_list ``=` `[[``3``], [``1``, ``7``], [``10``, ``2``, ``4``], [``8``, ``6``, ``5``, ``1``, ``4``]]` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))` `res ``=` `True``for` `idx ``in` `range``(``len``(test_list) ``-` `1``) :``    ` `    ``# flag off in case next length is not greater``    ``# than current``    ``if` `len``(test_list[idx ``+` `1``]) <``=` `len``(test_list[idx]):``        ``res ``=` `False``        ``break` `# printing result``print``(``"Are rows of increasing lengths ? : "` `+` `str``(res))`

Output:

The original list is : [, [1, 7], [10, 2, 4], [8, 6, 5, 1, 4]]

Are rows of increasing lengths ? : True

Method 2 : Using all() and list comprehension

In this, we test for next length being greater than the current length using len() and all() is used to check for all the rows.

## Python3

 `# initializing list``test_list ``=` `[[``3``], [``1``, ``7``], [``10``, ``2``, ``4``], [``8``, ``6``, ``5``, ``1``, ``4``]]` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))` `# checking for truth for all rows in matrix``res ``=` `all``(``len``(test_list[idx ``+` `1``]) > ``len``(test_list[idx]) ``for` `idx ``in` `range``(``len``(test_list) ``-` `1``))` `# printing result``print``(``"Are rows of increasing lengths ? : "` `+` `str``(res))`

Output:

The original list is : [, [1, 7], [10, 2, 4], [8, 6, 5, 1, 4]]

Are rows of increasing lengths ? : True

Method 3: Using len() and sort()

In this we will append length of each row to a new list, later we will check whether the initial list and  list after sorting are same or not.If same the length of rows are in increasing manner

## Python3

 `# initializing list``test_list ``=` `[[``3``], [``1``, ``7``], [``10``], [``8``, ``6``, ``5``, ``1``, ``4``]]` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))` `res ``=` `False``x``=``[]``for` `i ``in` `test_list:``    ``x.append(``len``(i))``a``=``x``x``=``x.sort()``if``(a``=``=``x):``    ``res``=``True``# printing result``print``(``"Are rows of increasing lengths ? : "` `+` `str``(res))`

Output

```The original list is : [, [1, 7], , [8, 6, 5, 1, 4]]
Are rows of increasing lengths ? : False```

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