How to flatten a list of lists in Python?

You can use for loop to flatten a list of lists in Python as shown below –

listoflists = [[1,2,3],[4,5],[6,7,8]]

flat_list = [item for sublist in listoflists for item in sublist]
print(flat_list)
print(type(flat_list))

## Returns
## [1, 2, 3, 4, 5, 6, 7, 8]
## <class 'list'>

listoflists = [[1,2,3],[4,5],[6,7,8]]

flat_list = [item for sublist in listoflists for item in sublist]

print(flat_list)

print(type(flat_list))

## Returns

## [1, 2, 3, 4, 5, 6, 7, 8]

Tags: FAQ, Python