Introduction to Python functions: functions and usage examples of the len function

Python function introduction: functions and usage examples of the len function

In Python programming, len() is a commonly used built-in function, which is used to return the incoming The length or number of elements of the object. This function can be used for different types of data structures such as strings, lists, tuples, dictionaries, and sets. The len() function is very simple and easy to use. This article will introduce the specific functions and usage examples of the len() function, and provide corresponding code.

Function of len() function:
The main function of len() function is to return the length or number of elements of the incoming object. The specific usage is as follows:
len(object)
Among them, object is a required parameter, which can be objects of different data types such as strings, lists, tuples, dictionaries, and sets.

Usage Example 1: String
A string is a sequence of characters, and the number of characters in the string can be obtained through the len() function. The following is a sample code:

str = "Hello, World!"
print(len(str))

The output result is: 13

Usage Example 2: List
The list is one of the commonly used data structures in Python, and the len() function can calculate the list The number of elements in . The following is a sample code:

list = [1, 2, 3, 4, 5]
print(len(list))

The output result is: 5

Usage Example 3: Tuple
The tuple is an immutable data structure, and you can also use the len() function to count the number of elements in a tuple. The following is a sample code:

tuple = (1, 2, 3, 4, 5)
print(len(tuple))

The output result is: 5

Usage Example 4: Dictionary
The dictionary is a key-value pair data structure in Python, the len() function You can count the number of keys in a dictionary. The following is a sample code:

dict = {"name": "Tom", "age": 25, "gender": "male"}
print(len(dict))

The output result is: 3

Usage Example 5: Set
A set is an unordered, non-repeating element data structure in Python, len () function can count the number of elements in the set. The following is a sample code:

set = {1, 2, 3, 4, 5}
print(len(set))

The output result is: 5

Summary:
Through the above sample code, we can see the use of the len() function in different data types methods and return results. The len() function is very flexible and convenient, and can help us quickly obtain the number or length of elements in various data structures. In actual programming, the len() function is often used in loops, conditional judgments and other scenarios to help us perform corresponding operations and processing.

It should be noted that the len() function can only calculate the length of iterable objects. For basic data types such as integers and floating point numbers, using the len() function will report an error. So when using the len() function, you need to ensure that the object passed in is iterable. In addition, for dictionaries, the len() function returns the number of key-value pairs in the dictionary, not the length of the dictionary.

By understanding and mastering the len() function, we can better write Python programs and implement more complex functions and logic. I hope the introduction in this article will be helpful to readers in the process of learning Python programming.

The above is the detailed content of Introduction to Python functions: functions and usage examples of the len function. For more information, please follow other related articles on the PHP Chinese website!