# Python | Check if a list is contained in another list

Given two lists A and B, write a Python program to Check if list A is contained in list B without breaking A’s order.

Examples:

```Input : A = [1, 2], B = [1, 2, 3, 1, 1, 2, 2]
Output : True

Input : A = ['x', 'y', 'z'], B = ['x', 'a', 'y', 'x', 'b', 'z']
Output : False
```

Approach #1 : Naive Approach

A simple naive approach is to use two for loops and check if the whole list A is contained within list B or not. If such a position is met in list A, then break the loop and return true, otherwise false

 `# Python3 program to Check if a list is  ` `# contained in another list without breaking order ` ` `  `def` `removeElements(A, B): ` `    ``for` `i ``in` `range``(``len``(B)``-``len``(A)``+``1``): ` `        ``for` `j ``in` `range``(``len``(A)): ` `            ``if` `B[i ``+` `j] !``=` `A[j]: ` `                ``break` `        ``else``: ` `            ``return` `True` `    ``return` `False` ` `  `# Driver code ` `A ``=` `[``1``, ``2``] ` `B ``=` `[``1``, ``2``, ``3``, ``1``, ``1``, ``2``, ``2``] ` `print``(removeElements(A, B)) `

Output:

```True
```

Approach #2 : List comprehension

A more efficient approach is to use List comprehension. We first initialize ‘n’ with length of A. Now use a for loop till len(B)-n and check in each iteration if `A == B[i:i+n]` or not.

 `# Python3 program to Remove elements of  ` `# list that repeated less than k times ` ` `  `def` `removeElements(A, B): ` `    ``n ``=` `len``(A) ` `    ``return` `any``(A ``=``=` `B[i:i ``+` `n] ``for` `i ``in` `range``(``len``(B)``-``n ``+` `1``)) ` `             `  `     `  `# Driver code ` `A ``=` `[``1``, ``2``] ` `B ``=` `[``1``, ``2``, ``3``, ``1``, ``1``, ``2``, ``2``] ` `print``(removeElements(A, B)) `

Output:

```True
```

Approach #3 : Using join and map module

Here we use join to join both lists to strings and then use in operator to check if list A is contained in B or not.

 `# Python3 program to Remove elements of  ` `# list that repeated less than k times ` ` `  ` `  `def` `removeElements(A, B): ` `    ``return` `', '``.join(``map``(``str``, A)) ``in` `', '``.join(``map``(``str``, B)) ` `             `  `# Driver code ` `A ``=` `[``'x'``, ``'y'``, ``'z'``] ` `B ``=` `[``'x'``, ``'a'``, ``'y'``, ``'x'``, ``'b'``, ``'z'``] ` `print``(removeElements(A, B)) `

Output:

```False
```

My Personal Notes arrow_drop_up 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.

Improved By : ManasChhabra2