Python | Consecutive elements grouping in list
Sometimes, while working with Python lists, we can have a problem in which we might need to group the list elements on basis of their respective consecutiveness. This kind of problem can occur while data handling. Let’s discuss certain way in which this task can be performed.
Method : Using enumerate() + groupby()
+ generator function + lambda
This task can be performed using the combination of above functions. In this, we create a generator function, in which we pass the list whose index-element are accessed using enumerate()
and grouped by consecutive elements using groupby()
and lambda. Works with Python2 only
# Python code to demonstrate working of # Consecutive elements grouping list # using enumerate() + groupby() + generator function + lambda import itertools # Utility Generator Function def groupc(test_list): for x, y in itertools.groupby( enumerate (test_list), lambda (a, b): b - a): y = list (y) yield y[ 0 ][ 1 ], y[ - 1 ][ 1 ] # initialize list test_list = [ 1 , 2 , 3 , 6 , 7 , 8 , 11 , 12 , 13 ] # printing original list print ( "The original list is : " + str (test_list)) # Consecutive elements grouping list # using enumerate() + groupby() + generator function + lambda res = list (groupc(test_list)) # printing result print ( "Grouped list is : " + str (res)) |
Output :
The original list is : [1, 2, 3, 6, 7, 8, 11, 12, 13] Grouped list is : [(1, 3), (6, 8), (11, 13)]