Python | Check if element exists in list of lists

Given a list of lists, the task is to determine whether the given element exists in any sublist or not. Given below are a few methods to solve the given task.

Method #1: Using any()

any() method return true whenever a particular element is present in a given iterator.

# Python code to demonstrate
# finding whether element
# exists in listof list

# initialising nested lists
ini_list = [[1, 2, 5, 10, 7],
            [4, 3, 4, 3, 21],
            [45, 65, 8, 8, 9, 9]]

elem_to_find = 8
elem_to_find1 = 0

# element exists in listof listor not?
res1 = any(elem_to_find in sublist for sublist in ini_list)
res2 = any(elem_to_find1 in sublist for sublist in ini_list)

# printing result
print(str(res1), "\n", str(res2))

Output:

True 
 False

Method #2: Using operator in

The ‘in’ operator is used to check if a value exists in a sequence or not. Evaluates to true if it finds a variable in the specified sequence and false otherwise.

# Python code to demonstrate
# finding whether element
# exists in listof list

# initialising nested lists
ini_list = [[1, 2, 5, 10, 7],
            [4, 3, 4, 3, 21],
            [45, 65, 8, 8, 9, 9]]

elem = 8
elem1 = 0

# element exists in listof listor not?
res1 = elem in (item for sublist in ini_list for item in sublist)
res2 = elem1 in (item for sublist in ini_list for item in sublist)

# printing result
print(str(res1), "\n", str(res2))

Output:

True 
 False

Method #3: Using itertools.chain()

Make an iterator that returns elements from the first iterable until it is exhausted, then proceeds to the next iterable, until all of the iterables are exhausted.

# Python code to demonstrate
# finding whether element
# exists in listof list
from  itertools import chain

# initialising nested lists
ini_list = [[1, 2, 5, 10, 7],
            [4, 3, 4, 3, 21],
            [45, 65, 8, 8, 9, 9]]

elem_to_find = 8
elem_to_find1 = 0

# element exists in listof listor not?
res1 = elem_to_find in chain(*ini_list)
res2 = elem_to_find1 in chain(*ini_list)

# printing result
print(str(res1), "\n", str(res2))

Output:

True 
 False