Python | Select dictionary with condition given key greater than k

In Python, sometimes we require to get only some of the dictionary required to solve the problem. This problem is quite common in web development that we require to get only the selective dictionary satisfying some given criteria. Let’s discuss certain ways in which this problem can be solved.

Method #1: Using list comprehension

# Python3 code to demonstrate
# filtering of a list of dictionary
# on basis of condition

# initialising list of dictionary
ini_list = [{'a':1, 'b':3, 'c':7}, {'a':3, 'b':8, 'c':17},
            {'a':78, 'b':12, 'c':13}, {'a':2, 'b':2, 'c':2}]

# printing initial list of dictionary
print ("initial_list", str(ini_list))

# code to filter list
# where c is greater than 10
res = [d for d in ini_list if d['c'] > 10]

# printing result
print ("resultant_list", str(res))

Output:

initial_list [{‘c’: 7, ‘b’: 3, ‘a’: 1}, {‘c’: 17, ‘b’: 8, ‘a’: 3}, {‘c’: 13, ‘b’: 12, ‘a’: 78}, {‘c’: 2, ‘b’: 2, ‘a’: 2}]
resultant_list [{‘c’: 17, ‘b’: 8, ‘a’: 3}, {‘c’: 13, ‘b’: 12, ‘a’: 78}]

Method #2: Using lambda and filter

# Python3 code to demonstrate
# filtering of list of dictionary
# on basis of condition

# initialising list of dictionary
ini_list = [{'a':1, 'b':3, 'c':7}, {'a':3, 'b':8, 'c':17},
            {'a':78, 'b':12, 'c':13}, {'a':2, 'b':2, 'c':2}]

# printing initial list of dictionary
print ("initial_list", str(ini_list))

# code to filter list
# where c is less than 10
res = list(filter(lambda x:x["c"] > 10, ini_list ))

# printing result
print ("resultant_list", str(res))

Output:

initial_list [{‘b’: 3, ‘c’: 7, ‘a’: 1}, {‘b’: 8, ‘c’: 17, ‘a’: 3}, {‘b’: 12, ‘c’: 13, ‘a’: 78}, {‘b’: 2, ‘c’: 2, ‘a’: 2}]
resultant_list [{‘c’: 17, ‘b’: 8, ‘a’: 3}, {‘c’: 13, ‘b’: 12, ‘a’: 78}]

Method #3: Using dict comprehension and list comprehension

# Python3 code to demonstrate
# filtering of list of dictionary
# on basis of condition

# initialising list of dictionary
ini_list = [{'a':1, 'b':3, 'c':7}, {'a':3, 'b':8, 'c':17},
            {'a':78, 'b':12, 'c':13}, {'a':2, 'b':2, 'c':10}]

# printing initial list of dictionary
print ("initial_list", str(ini_list))

# code to filter list
# where c is more than 10

res = [{ k:v for (k, v) in i.items()}
        for i in ini_list if i.get('c') > 10]

# printing result
print ("resultant_list", str(res))

Output:

initial_list [{‘a’: 1, ‘c’: 7, ‘b’: 3}, {‘a’: 3, ‘c’: 17, ‘b’: 8}, {‘a’: 78, ‘c’: 13, ‘b’: 12}, {‘a’: 2, ‘c’: 10, ‘b’: 2}]
resultant_list [{‘a’: 3, ‘c’: 17, ‘b’: 8}, {‘a’: 78, ‘c’: 13, ‘b’: 12}]