Python – Convert List to key-value list by prefix grouping
Given a list, convert it to consecutive key-value lists, grouping by prefix.
Input : test_list = [“GFG-1”, 4, 6, “GFG-2”, 3, “GFG-3”, 9, 2], temp = “GF”
Output : {‘GFG-1’: [4, 6], ‘GFG-2’: [3], ‘GFG-3’: [9, 2]}
Explanation : All grouped till next prefix.Input : test_list = [“MRK-1”, 4, 6, “MRK-2”, 3, “MRK-3”, 9, 2], temp = “MR”
Output : {‘MRK-1’: [4, 6], ‘MRK-2’: [3], ‘MRK-3’: [9, 2]}
Explanation : All grouped till next prefix, “MR”.
Method : Using groupby() + startswith() + lambda
The combination of above functions can be used to solve this problem. In this, we employ grouping of all elements by prefix using groupby() and lambda functions assists in performing segregation of prefix for grouping.
Python3
# Python3 code to demonstrate working of # Convert List to key-value list by prefic grouping# Using groupby() + startswith() + lambdafrom itertools import groupby # initializing listtest_list = ["GFG-1", 4, 6, 7, "GFG-2", 2, 3, "GFG-3", 9, 2, 4, 6] # printing original listprint("The original list : " + str(test_list)) # initializing prefix temp = "GFG" res = {}# extracting result from grouped by prefixfor key, val in groupby(test_list, lambda ele: str(ele).startswith(temp)): # checking for existing key if key: k = next(val) else: res[k] = list(val) # printing result print("The constructed dictionary : " + str(res)) |
Output
The original list : ['GFG-1', 4, 6, 7, 'GFG-2', 2, 3, 'GFG-3', 9, 2, 4, 6]
The constructed dictionary : {'GFG-1': [4, 6, 7], 'GFG-2': [2, 3], 'GFG-3': [9, 2, 4, 6]}
.png)
