How to Create a Dictionary in Python?

Dictionaries are super useful in Python! Think of them like a fancy box where you can store lots of different things, just like how you’d use a map. They’re not picky about the order you put things in. You can add stuff, remove stuff, and change stuff whenever you want because dictionaries are flexible like that. The cool thing is they’re really quick to find stuff inside, and they don’t use up too much memory either.

So, if you need a quick and easy way to store and find data, dictionaries are your best friend!

Create a Dictionary in Python

Creating a dictionary in Python is easy peasy! Just wrap your elements inside curly braces {}, and separate them with commas. Here are some examples to show you how it’s done.

Define a Dictionary with Items

In this example, we start with an empty dictionary called D. Then, we take elements from a Python list called L and put them into the dictionary. Each sublist in L has two elements: the first one becomes the key, and the second one becomes the value. We do this dynamically, meaning we add key-value pairs as needed.

# Declare an empty dictionary
D = {}
# Python list with sublists containing key-value pairs
L = [['a', 1], ['b', 2], ['c', 3]]
# Add elements from the list into the dictionary dynamically
for sublist in L:
key = sublist[0]
value = sublist[1]
D[key] = value
# Print the resulting dictionary
print(D)

Output:

{‘a’: 1, ‘b’: 2, ‘c’: 3}

Understanding Keys and Values in Dictionaries

In this demonstration, we’ll expand the existing Python dictionary by adding another element. We’ll be given both the key and the value separately, and we’ll insert this pair into the dictionary called my_dict.

Example

# Existing dictionary
my_dict = {'a': 1, 'b': 2, 'c': 3}
# New key and value to be added
new_key = 'd'
new_value = 4
# Adding the new key-value pair to the dictionary
my_dict[new_key] = new_value
# Printing the updated dictionary
print(my_dict)

Output

{‘a’: 1, ‘b’: 2, ‘c’: 3, ‘d’: 4}

Built-in Dictionary Functions Methods in Python:

We can create a dictionary in Python using the built-in function dict(). In this example, we start by creating an empty dictionary with curly braces {}. Then, we utilize the dict() function by passing a list to it.

Example

# Creating an empty dictionary using curly braces {}
empty_dict = {}
# List containing key-value pairs
key_value_pairs = [('a', 1), ('b', 2), ('c', 3)]
# Creating a dictionary using dict() function and passing the list
created_dict = dict(key_value_pairs)
# Printing the created dictionary
print(created_dict)

Output

{‘a’: 1, ‘b’: 2, ‘c’: 3}

Conclusion

In conclusion, dictionaries in Python can be created using the built-in dict() function. This function allows us to initialize a dictionary by passing a list of key-value pairs to it. By leveraging this method, we can efficiently create dictionaries without explicitly defining each key-value pair.