What does import do in Python?

What Does Import in Python?

Python is a high-level, multi-paradigm programming language that is widely used for various purposes such as web development, scientific computing, and data analysis. One of the fundamental concepts in Python is import, which is used to bring in external modules and functionality into a Python program.

What is Import?

In Python, import is a statement that allows you to bring in modules, functions, and variables from another module into your current Python program. It is used to inject external functionality into your program and make it more modular and reusable.

Types of Imports

There are two types of imports in Python:

• Built-in Imports: These are imports of modules that come pre-installed with Python. Examples include math, statistics, and time.
• Third-Party Imports: These are imports of modules from external sources, such as libraries or frameworks. Examples include numpy, pandas, and requests.

Importing Modules

To import a module, you need to use the import statement followed by the name of the module you want to import. For example:

import math

print(math.pi)

In this example, we are importing the math module and assigning its pi variable to a variable.

Importing Functions

Imports can also be used to import specific functions from a module. For example:

import math

from math import pi

print(pi)

In this example, we are importing the pi function from the math module.

Importing Modules with Multiple Names

Imports can also be used to import multiple names from a module. For example:

import math

import statistics

print(math.sin(1.0))

In this example, we are importing the sin function from the math module and the statistics module.

Importing Modules as Names

Imports can also be used to import modules as names. For example:

import statistics

stats = statistics

print(stats.mean([1, 2, 3, 4, 5]))

In this example, we are importing the statistics module and assigning it to the stats variable.

Types of Imports

There are several types of imports in Python:

• Module-Level Import: This is the most common type of import in Python. It is used to import a module as a whole.
• Function-Level Import: This is used to import a specific function from a module.
• Class-Level Import: This is used to import a class from a module.
• Namespace-Level Import: This is used to import all members of a module, including functions and classes.

Importing Modules from Files

Imports can also be used to import modules from files. For example:

import os

import sys

import json

with open('data.json') as f:

    data = json.load(f)

In this example, we are importing the os, sys, and json modules from a file named data.json.

Importing Modules with Specific Paths

Imports can also be used to import modules with specific paths. For example:

import os.path

import sys.path

import math

print(os.path.join(sys.path[0], 'non_existent_file.py'))

In this example, we are importing the os.path module and assigning its join function to a variable.

Best Practices for Importing Modules

Here are some best practices for importing modules in Python:

• Use import statements: Always use import statements to bring in external modules.
• Use explicit import statements: Avoid using implicit imports (e.g. from module import *) and instead use explicit import statements.
• Use specific paths: When importing modules with specific paths, use explicit import statements and avoid relying on implicit imports.
• Test your imports: Always test your imports to ensure that they are working correctly.

Conclusion

In conclusion, import is a fundamental concept in Python that allows you to bring in external modules and functionality into your Python program. By understanding the different types of imports, how to import modules, and best practices for importing modules, you can write more modular, reusable, and efficient Python code.