What are the naming rules for Python language variables?

Python language variable naming rules include the composition of variable names, naming conventions and following naming conventions. Detailed introduction: 1. The composition of the variable name. The first character of the variable name must be a letter. It cannot start with a number, but it can contain numbers. It is case-sensitive and cannot be a Python keyword or the name of a built-in function; 2. Naming convention, variable names should be descriptive and be able to clearly express the meaning of the variable. Usually, lowercase letters are used to name variables, and underscores can be used to separate words, etc.

The operating system for this tutorial: Windows 10 system, Python version 3.11.4, DELL G3 computer.

Python’s variable naming rules are relatively flexible, but there are also some conventional rules that need to be followed. Below I will introduce the variable naming rules in Python in detail.

1. Composition of variable names: Variable names in Python can contain letters, numbers and underscores, but must follow the following rules:

• The first character of a variable name must be a letter (including uppercase and lowercase letters) or an underscore (_).

• Variable names cannot start with numbers, but they can contain numbers.

• Variable names are case-sensitive. For example, "name" and "Name" are two different variable names.

• The variable name cannot be a Python keyword (such as if, else, for, etc.) or the name of a built-in function (such as print, len, etc.).

2. Naming convention: Although variable names in Python can flexibly combine letters, numbers, and underscores, they usually follow the following naming conventions and conventions:

• Variable names should be descriptive and clearly express what the variable represents, which helps improve the readability of the code.

• Usually lowercase letters are used to name variables, and underscores can be used to separate words. This naming style is called underline naming (snake_case), such as "first_name", "user_age", etc.

• For constants, usually use all uppercase letters to name them, and use underscores to separate words, such as "MAX_LENGTH", "DEFAULT_VALUE", etc. Although Python There are no true constants in , but this naming convention indicates that the variable should be treated as a constant.

3. Follow naming conventions: Although Python's variable names can be quite free, in order to follow the same conventions with other Python programmers, it is generally recommended to follow the following Naming convention:

• Use descriptive variable names: Variable names should be clear, descriptive, and accurately express what the variable represents, which helps others understand the code.

• Use lowercase letters and underscores: Naming variables using the underscore naming method (snake_case) can improve the readability of the code, maintain consistency, and comply with the conventions of the Python community.

• Avoid using a single character as a variable name unless the meaning of the character is very clear and common, such as using "i" as a loop variable.

• Be careful to avoid using variable names starting with a single underscore or a double underscore, because these naming methods have special meanings in Python.

For example, in Python, the correct and standardized variable naming may be as follows:

first_name = "Alice"
user_age = 30
max_attempts = 3

In general, Python’s variable naming rules are very Flexible, but to improve code readability and interoperability with other Python For programmer consistency, it is recommended to follow the variable naming conventions and conventions mentioned above. This makes the code easier to understand and maintain. Hope this information is helpful to you!

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