Python – Conditional Join Dictionary List
Given 2 dictionaries list, the task is to write a Python program to perform conditional join i.e add keys, based upon similarity of particular key in similar index dictionary.
Example:
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Input : test_list1 = [{“gfg” : 1, “is” : 3, “best”: 2}, {“gfg” : 1, “best” : 6}, {“all” : 7, “best” : 10} ],
test_list2 = [{“good” : 4, “best”: 2}, {“geeks” : 2, “best” : 3 }, {“CS” : 2, “best” : 10 } ], test_key = “best”
Output : [{‘gfg’: 1, ‘is’: 3, ‘best’: 2, ‘good’: 4}, {‘gfg’: 1, ‘best’: 6}, {‘all’: 7, ‘best’: 10, ‘CS’: 2}]
Explanation : best has 2 in both dictionaries of 0th index, hence at index 0, dictionaries are merged.
Input : test_list1 = [{“gfg” : 1, “is” : 3, “best”: 3}, {“gfg” : 1, “best” : 6}, {“all” : 7, “best” : 10} ],
test_list2 = [{“good” : 4, “best”: 2}, {“geeks” : 2, “best” : 3 }, {“CS” : 2, “best” : 10 } ], test_key = “best”
Output : [{‘gfg’: 1, ‘is’: 3, ‘best’: 3}, {‘gfg’: 1, ‘best’: 6}, {‘all’: 7, ‘best’: 10, ‘CS’: 2}]
Explanation : best has 10 in both dictionaries of 2nd index, hence at index 2, dictionaries are merged.
Method : Using next() + update()
In this, we use generator expression to check if dictionary’s key matches the similar index dictionary key, if yes, then all the corresponding keys are merged using update().
Python3
# Python3 code to demonstrate working of# Conditional Join Dictionary List# Using update() + next()# initializing liststest_list1 = [{"gfg": 1, "is": 3, "best": 2}, { "gfg": 1, "best": 6}, {"all": 7, "best": 10}]test_list2 = [{"good": 4, "best": 2}, { "geeks": 2, "best": 3}, {"CS": 2, "best": 10}]# printing original listprint("The original list 1 is : " + str(test_list1))print("The original list 2 is : " + str(test_list2))# initializing test keytest_key = "best"for sub1 in test_list1: # checking for matching key temp = next( (itm for itm in test_list2 if sub1[test_key] == itm[test_key]), None) if(temp): # performing update sub1.update(temp)# printing resultprint("Joined result : " + str(test_list1)) |
Output:
The original list 1 is : [{‘gfg’: 1, ‘is’: 3, ‘best’: 2}, {‘gfg’: 1, ‘best’: 6}, {‘all’: 7, ‘best’: 10}]
The original list 2 is : [{‘good’: 4, ‘best’: 2}, {‘geeks’: 2, ‘best’: 3}, {‘CS’: 2, ‘best’: 10}]
Joined result : [{‘gfg’: 1, ‘is’: 3, ‘best’: 2, ‘good’: 4}, {‘gfg’: 1, ‘best’: 6}, {‘all’: 7,
‘best’: 10, ‘CS’: 2}]
