concat_same_key_values.py

test_list = [{'gfg' : [1, 5, 6, 7], 'good' : [9, 6, 2, 10], 'CS' : [4, 5, 6]},
             {'gfg' : [5, 6, 7, 8], 'CS' : [5, 7, 10]},
             {'gfg' : [7, 5], 'best' : [5, 7]}]

# Concatenate Similar Key values
# Using loop
res = dict()
for dict in test_list:
    for list in dict:
        if list in res:
            res[list] += (dict[list])
        else:
            res[list] = dict[list]
            
#The original list is : [{'CS': [4, 5, 6], 'good': [9, 6, 2, 10], 'gfg': [1, 5, 6, 7]}, {'CS': [5, 7, 10], 'gfg': [5, 6, 7, 8]}, {'best': [5, 7], 'gfg': [7, 5]}]
#The concatenated dictionary : {'gfg': [1, 5, 6, 7, 5, 6, 7, 8, 7, 5], 'good': [9, 6, 2, 10], 'best': [5, 7], 'CS': [4, 5, 6, 5, 7, 10]}