Python | Sort given list of dictionaries by date Last Updated : 14 Mar, 2023 Comments Improve Suggest changes Like Article Like Report Given a list of dictionary, the task is to sort the dictionary by date. Let's see a few methods to solve the task. Method #1: Using naive approach Python3 # Python code to demonstrate # sort a list of dictionary # where value date is in string # Initialising list of dictionary ini_list = [{'name':'akash', 'd.o.b':'1997-03-02'}, {'name':'manjeet', 'd.o.b':'1997-01-04'}, {'name':'nikhil', 'd.o.b':'1997-09-13'}] # printing initial list print ("initial list : ", str(ini_list)) # code to sort list on date ini_list.sort(key = lambda x:x['d.o.b']) # printing final list print ("result", str(ini_list)) Output: initial list : [{'name': 'akash', 'd.o.b': '1997-03-02'}, {'name': 'manjeet', 'd.o.b': '1997-01-04'}, {'name': 'nikhil', 'd.o.b': '1997-09-13'}] result [{'name': 'manjeet', 'd.o.b': '1997-01-04'}, {'name': 'akash', 'd.o.b': '1997-03-02'}, {'name': 'nikhil', 'd.o.b': '1997-09-13'}] The time complexity of the above Python code is O(n log n), where 'n' is the number of dictionaries in the list. The auxiliary space complexity of the code is O(1), as it only uses a constant amount of additional space, regardless of the size of the input. Method #2: Using datetime.strptime and lambda Python3 # Python code to demonstrate # sort a list of dictionary # where value date is in a string from datetime import datetime # Initialising list of dictionary ini_list = [{'name':'akshat', 'd.o.b':'1997-09-01'}, {'name':'vashu', 'd.o.b':'1997-08-19'}, {'name':'manjeet', 'd.o.b':'1997-01-04'}, {'name':'nikhil', 'd.o.b':'1997-09-13'}] # printing initial list print ("initial list : ", str(ini_list)) # code to sort list on date ini_list.sort(key = lambda x: datetime.strptime(x['d.o.b'], '%Y-%m-%d')) # printing final list print ("result", str(ini_list)) Output: initial list : [{'d.o.b': '1997-09-01', 'name': 'akshat'}, {'d.o.b': '1997-08-19', 'name': 'vashu'}, {'d.o.b': '1997-01-04', 'name': 'manjeet'}, {'d.o.b': '1997-09-13', 'name': 'nikhil'}] result [{'d.o.b': '1997-01-04', 'name': 'manjeet'}, {'d.o.b': '1997-08-19', 'name': 'vashu'}, {'d.o.b': '1997-09-01', 'name': 'akshat'}, {'d.o.b': '1997-09-13', 'name': 'nikhil'}] Method #3: Using operator.itemgetter Python3 # Python code to demonstrate # sort a list of dictionary # where value date is in string import operator # Initialising list of dictionary ini_list = [{'name':'akash', 'd.o.b':'1997-03-02'}, {'name':'manjeet', 'd.o.b':'1997-01-04'}, {'name':'nikhil', 'd.o.b':'1997-09-13'}] # printing initial list print ("initial list : ", str(ini_list)) # code to sort list on date ini_list.sort(key = operator.itemgetter('d.o.b')) # printing final list print ("result", str(ini_list)) Output: initial list : [{'d.o.b': '1997-03-02', 'name': 'akash'}, {'d.o.b': '1997-01-04', 'name': 'manjeet'}, {'d.o.b': '1997-09-13', 'name': 'nikhil'}] result [{'d.o.b': '1997-01-04', 'name': 'manjeet'}, {'d.o.b': '1997-03-02', 'name': 'akash'}, {'d.o.b': '1997-09-13', 'name': 'nikhil'}] Comment More infoAdvertise with us Next Article Python | Sort given list of dictionaries by date garg_ak0109 Follow Improve Article Tags : Python Python Programs Python dictionary-programs Python-sort Practice Tags : python Similar Reads Sort List of Dictionaries by Multiple Keys - Python We are given a list of dictionaries where each dictionary contains various keys and our task is to sort the list by multiple keys. 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