Mapping Keys to Multiple Values in a Dictionary (Python)

multidict.py

# Mapping Keys to Multiple Values in a Dictionary with defaultdict (multidict)

# A dictionary is a mapping where each key is mapped to a single value. If you want to
# map keys to multiple values, you need to store the multiple values in another container
# such as a list or set.

from collections import defaultdict
first_dict = {'a': 1, 'b': 2, 'c': 3}
second_dict = defaultdict(list)
for key in first_dict:
        second_dict[key] = list(first_dict.values())
        print(second_dict)

# defaultdict(<type 'list'>, {'a': [1, 3, 2]})
# defaultdict(<type 'list'>, {'a': [1, 3, 2], 'c': [1, 3, 2]})
# defaultdict(<type 'list'>, {'a': [1, 3, 2], 'c': [1, 3, 2], 'b': [1, 3, 2]})

multidict2.py

# Mapping Keys to Multiple Values in a Dictionary (multidict)

# A dictionary is a mapping where each key is mapped to a single value. If you want to
# map keys to multiple values, you need to store the multiple values in another container
# such as a list or set.

first_dict = {'a': 1, 'b': 2, 'c': 3}
second_dict = {}
for key in first_dict:
	second_dict[key] = list(first_dict.values())
	print(second_dict)

# {'a': [1, 3, 2]}
# {'a': [1, 3, 2], 'c': [1, 3, 2]}
# {'a': [1, 3, 2], 'c': [1, 3, 2], 'b': [1, 3, 2]}