Python – Flatten List to individual elements
Sometimes, while working with Python list, we can have a problem in which we need to perform flatten of list, i.e convert a mixed list to flattened one. This can have application in domains which use 1D lists as input. Lets discuss certain ways in which this task can be performed.
Method #1 : Using loop + isinstance()
The combination of above functionalities can be used to perform this task. In this, we check for instance of list and flatten it and rest of elements we add to list brutely.
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# Python3 code to demonstrate # Flatten List to individual elements# using loop + isinstance() def flatten(test_list): if isinstance(test_list, list): temp = [] for ele in test_list: temp.extend(flatten(ele)) return temp else: return [test_list] # Initializing listtest_list = ['gfg', 1, [5, 6, 'geeks'], 67.4, [5], 'best'] # printing original listprint("The original list is : " + str(test_list)) # Flatten List to individual elements# using loop + isinstance()res = flatten(test_list) # printing result print ("The List after flattening : " + str(res)) |
The original list is : [‘gfg’, 1, [5, 6, ‘geeks’], 67.4, [5], ‘best’]
The List after flattening : [‘gfg’, 1, 5, 6, ‘geeks’, 67.4, 5, ‘best’]
Method #2 : Using chain() + isinstance()
This is yet another way in which this task can be performed. In this we perform the task of iteration using chain() and checking for list instance is done using isinstance().
# Python3 code to demonstrate # Flatten List to individual elements# using chain() + isinstance()from itertools import chain # Initializing listtest_list = ['gfg', 1, [5, 6, 'geeks'], 67.4, [5], 'best'] # printing original listprint("The original list is : " + str(test_list)) # Flatten List to individual elements# using chain() + isinstance()res = list(chain(*[ele if isinstance(ele, list) else [ele] for ele in test_list])) # printing result print ("The List after flattening : " + str(res)) |
The original list is : [‘gfg’, 1, [5, 6, ‘geeks’], 67.4, [5], ‘best’]
The List after flattening : [‘gfg’, 1, 5, 6, ‘geeks’, 67.4, 5, ‘best’]
