Python: Count number of items in a dictionary value that is a list

Last update on March 27 2025 12:58:03 (UTC/GMT +8 hours)

34. Count Number of Items in Dictionary Value That is a List

Write a Python program to count the number of items in a dictionary value that is a list.

Visual Presentation:

Sample Solution:

Python Code:

# Create a dictionary 'dict' with names as keys and lists of subjects as values.
dict =  {'Alex': ['subj1', 'subj2', 'subj3'], 'David': ['subj1', 'subj2']}

# Calculate the total number of subjects by summing the lengths of the lists (values) in the dictionary.
ctr = sum(map(len, dict.values()))

# Print the total count of subjects.
print(ctr) 

Sample Output:

5

For more Practice: Solve these Related Problems:

• Write a Python program to iterate over a dictionary and for each key whose value is a list, print the count of items in that list.
• Write a Python program to use dictionary comprehension to create a new dictionary mapping each key to the length of its list value.
• Write a Python program to sum the number of items across all list values in a dictionary.
• Write a Python program to implement a function that returns the total count of elements in all list-type values in a dictionary.

Python Code Editor:

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