An introduction to different types of identifiers in Python and their uses

Introduction to the types and usage of Python identifiers

Identifiers are names used to name variables, functions, classes, etc. in Python. In Python, identifiers include variable names, function names, class names, etc., which have certain naming rules and conventions. This article will introduce the types of Python identifiers and their usage, and provide specific code examples.

1. Variable name

The variable name is an identifier used to save data. In Python, variable names need to follow the following rules:

• Variable names consist of letters, numbers, and underscores, and cannot start with a number.
• Variable names are case-sensitive. For example, "number" and "Number" are two different variable names.
• Variable names cannot use Python keywords as names, such as if, for, while, etc.

The following is an example of a variable name:

number = 10

2. Function name

The function name is the identifier used to define the function. In Python, function names need to follow the following rules:

• Function names consist of letters, numbers, and underscores, and cannot start with a number.
• Function names are case-sensitive.
• Function names cannot use Python keywords as names.

The following is an example of a function name:

def add_numbers(a, b):
    return a + b

3. Class name

The class name is the identifier used to define the class. In Python, class names need to follow the following rules:

• Class names start with a capital letter and consist of letters, numbers, and underscores.
• Class names are case-sensitive.
• Class names cannot use Python keywords as names.

The following is an example of a class name:

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def say_hello(self):
        print("Hello, my name is", self.name)

4. Module name

The module name is the identifier used to define the module. In Python, module names need to follow the following rules:

• Module names consist of letters, numbers, and underscores.
• Module names are case-sensitive.
• The module name cannot use Python keywords as the name.

The following is an example of a module name:

# 模块名为module_example.py
def greeting(name):
    print("Hello,", name)

number = 10

Summary:

In Python, identifiers include variable names, function names, class names, module names, etc. . They are used to name variables, functions, classes and modules respectively, and need to comply with certain naming rules and conventions. By using identifiers appropriately, we can write code that is clearer and easier to understand.

(Total word count: about 500 words)

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