How to Find the Length of a Map in Python

In this tutorial, we are going to learn how to find the length of a map in Python.
Mapping represents the connection between two data sets or a relation between the elements of two data sets.

Python includes several mapping types and the main one is the dictionary. Determining the length of a map is easy – it’s the same as finding the length of a dictionary.

Step 1: Creating a Dictionary

Before finding the length, we have to establish a dictionary. In Python, a dictionary is created with curly brackets {}. Here is an example:

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my_dict = {
    "Fruit": "Apple",
    "Color": "Red",
    "Size": "Medium"
}

Step 2: Using the len() Function

The built-in Python function len() returns the number of items in an object. When the object is a dictionary, len() returns the number of key-value pairs. Here is how you can apply it:

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print("Length : %d" % len (my_dict))

This should return:

Length : 3

Step 3: Checking for Empty dictionaries

If a dictionary is empty, the len() function will return 0:

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empty_dict = {}
print("Length : %d" % len (empty_dict))

This should return:

Length : 0

Code:

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my_dict = {
    "Fruit": "Apple",
    "Color": "Red",
    "Size": "Medium"
}
 
print("Length : %d" % len (my_dict))
 
empty_dict = {}
print("Length : %d" % len (empty_dict))

Conclusion:

Now you know how to count the number of mappings in a dictionary. The trick lies in the built-in Python function len(), which counts the number of key-value pairs. It’s important to remember that len() will return 0 if there are no items in the dictionary. Keep practicing and enhancing your Python skills!