What is Len() in Python With Example

Categories Python

Here’s an example of how to use the len() function in Python:

my_string = "Hello, world!"
string_length = len(my_string)
print("The length of the string is:", string_length)
Code language: Python (python)

In this example, we have a string variable called my_string with the value “Hello, world!”. We use the len() function to determine the length of the string, which returns an integer representing the number of characters in the string. We store the result in the variable string_length and then print it out using the print() function.

When you run this code, the output will be:

The length of the string is: 13Code language: Python (python)

The len() function can be used with other data types as well, such as lists, tuples, and dictionaries, to determine the number of elements they contain.

How does Len function work in Python?


The len() function in Python is used to determine the length or the number of elements in a given sequence, such as a string, list, tuple, or dictionary. Its functionality depends on the type of object it is called on.

Here’s a brief overview of how the len() function works for different data types:

  • Strings: When len() is called on a string, it returns the number of characters in the string, including whitespace and punctuation.
  • Lists and Tuples: For lists and tuples, len() returns the number of elements in the sequence. Each item in the list or tuple is counted as a separate element.
  • Dictionaries: In the case of dictionaries, len() returns the number of key-value pairs present in the dictionary.

The len() function is implemented by calling the __len__() method of the object it is applied to. Many built-in types, such as strings, lists, tuples, and dictionaries, have their own __len__() method defined, which allows the len() function to work seamlessly with these types.

It’s important to note that the len() function raises a TypeError if it is called on an object that doesn’t support the concept of length or doesn’t have a __len__() method defined.

In summary, the len() function is a convenient way to determine the size or length of a sequence-like object in Python.

What is the range Len ()) in Python?


In Python, the range() function and the len() function are separate and unrelated functions with different purposes.

The len() function, as discussed earlier, is used to determine the length or the number of elements in a given sequence, such as a string, list, tuple, or dictionary.

On the other hand, the range() function in Python is used to generate a sequence of numbers. It creates an iterable object that represents a sequence of numbers within a specified range. The range() function takes one, two, or three arguments: range(stop), range(start, stop), or range(start, stop, step).

Here are a few examples of using the range() function:

1. range(stop): Generates a sequence of numbers from 0 to stop-1.

for i in range(5):
    print(i)Code language: Python (python)

Output:

0
1
2
3
4Code language: Python (python)

2. range(start, stop): Generates a sequence of numbers from start to stop-1.

for i in range(2, 7):
    print(i)Code language: Python (python)

Output:

2
3
4
5
6Code language: Python (python)

3. range(start, stop, step): Generates a sequence of numbers from start to stop-1 with a specified step size.

for i in range(1, 10, 2):
    print(i)Code language: Python (python)

Output:

1
3
5
7
9Code language: Python (python)

In summary, the len() function is used to determine the length of a sequence, while the range() function is used to generate a sequence of numbers within a specified range.

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  • I am a middle python software engineer with a bachelor's degree in Software Engineering from Kharkiv National Aerospace University. My expertise lies in Python, Django, Flask, Docker, REST API, Odoo development, relational databases, and web development. I am passionate about creating efficient and scalable software solutions that drive innovation in the industry.

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