Introduction to Python functions: Usage and examples of __import__ function

Introduction to Python functions: Usage and examples of __import__ function

As a high-level programming language, Python’s powerful function library and how to use functions are also attractive to more and more people. One of the reasons why there are more and more developers and enthusiasts. In Python, the built-in __import__ function is a very powerful but rarely used function, which is used to dynamically import modules. It receives a static module name and returns the imported module object.

Syntax:
import (name[, globals[, locals[, fromlist[, level]]]])

The following is a detailed explanation of the function parameters :

name: Specify the name of the module to be imported.
globals: This should be a dictionary which will represent the global namespace.
locals: This should be a dictionary which will represent the local namespace.
fromlist: Specify a list of tuples representing objects to be imported from the module.
level: This is used to specify the level of the module relative to the installed part of the imported module. This parameter is of type integer.

Example 1: Importing the math module

Let’s look at a simple example of using the __import__ function to import the math module.

#导入math模块
math_module = __import__('math')

#求平方根
print(math_module.sqrt(2))

The output result is 1.4142135623730951.

Example 2: Import sys module

Let’s look at a more practical example. In Python, the sys module is a standard library built into Python. This module provides many functions and variables for interacting with the Python interpreter.

# 导入sys模块
sys_module = __import__('sys')

# 获取Python版本
print(sys_module.version)

# 获取Python解释器路径
print(sys_module.executable)

The output result is:

3.7.11 (default, Jul 27 2021, 09:42:27) [MSC v.1916 64 bit (AMD64)]
D:Program Files (x86)PythonPython37-32python.exe

Through the above code example, we can see that the __import__ function can very conveniently import the required functions or variables from the module. This way compares Flexible, especially suitable for dynamically loading modules as needed at runtime.

Summary:
The __import__ function allows Python code to import modules at runtime, making Python programs more flexible and maintainable. The __import__ function is often used to dynamically import modules and import and reload modules.

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