len() function returns the number of items present in an object. It can be used with strings, lists, tuples, dictionaries, sets and other container types to determine their size.
text = "Programming"
print(len(text))
Output
11
Explanation: len(text) calculates the number of characters in the string, "Programming" contains 11 characters and function returns 11, which is then displayed using print().
Syntax
len(object)
- Parameter: object is a sequence (such as a string, list, tuple) or collection (such as a dictionary, set) whose length is to be calculated.
- Returns: An integer value indicating the number of items in the object.
Examples
Example 1: In this example, we use the len() function to find the number of elements in a list, tuple and dictionary.
fruits = ["Apple", "Mango", "Orange", "Grapes"]
print(len(fruits))
numbers = (10, 20, 30, 40)
print(len(numbers))
student = {"name": "Emma", "age": 21, "city": "London"}
print(len(student))
Output
4 4 3
Explanation:
- len(fruits) returns 4 because the list contains four elements.
- len(numbers) returns 4 because the tuple contains four values.
- len(student) returns 3 because the dictionary contains three key-value pairs.
Example 2: In this example, we use the len() function to find the length of an empty list.
a = []
print(len(a))
Output
0
Explanation: Since the list is empty, len() returns 0, indicating there are no elements inside it.
Example 3: In this example, we use len() with range() to access and display each element of a list using its index.
a = [10, 20, 30, 40, 50]
for i in range(len(a)):
print("Index:", i, "Value:", a[i])
Output
Index: 0 Value: 10 Index: 1 Value: 20 Index: 2 Value: 30 Index: 3 Value: 40 Index: 4 Value: 50
Explanation: range() and len() are used to iterate over the list a by index. len(a) gives the total number of elements and range(len(a)) provides the index sequence. In each iteration, a[i] accesses the value at index i.
