Modules
A module is a single Python file containing definitions and statements. It can define functions, classes, and variables. Modules help organize code into logical units and promote code reusability.
Key points:
- A module is a
.py
file. - Contains functions, classes, and variables.
- Imported using
import
statement. - Example:
math
module,random
module.
Example:
Python
# my_module.py
def greet(name):
print("Hello,", name)
def add(x, y):
return x + y
Packages
A package is a directory of Python modules that are organized into a hierarchical structure. It allows for better organization and management of large codebases.
Key points:
- A package is a directory containing modules.
- Must contain an
__init__.py
file. - Can contain sub-packages.
- Imported using
import
statement with dot notation.
Example:
mypackage/
__init__.py
module1.py
module2.py
subpackage/
__init__.py
module3.py
Importing from a package:
Python
import mypackage.module1
from mypackage.subpackage import module3
Relationship between Modules and Packages
- A module is a single file, while a package is a directory containing modules.
- Packages help organize multiple modules into a hierarchical structure.
- Modules provide reusable code, while packages provide a way to structure and manage larger codebases.
Benefits of using Modules and Packages
- Code Reusability: Modules and packages promote code reuse.
- Organization: Help structure code into logical units.
- Namespace Management: Prevent naming conflicts.
- Modularity: Break down complex systems into smaller, manageable parts.
By understanding modules and packages, you can write more organized, efficient, and maintainable Python code.
What is a package in Python?
A package is a directory containing multiple modules and potentially sub-packages. It’s a way to structure larger codebases.
Why use modules and packages?
They improve code organization, reusability, and maintainability.
How do I create a module?
Create a Python file with a .py
extension.
How do I import a module?
Use the import
statement followed by the module name.
Can I have multiple modules in a single file?
No, a module is a single Python file.
What is the __init__.py
file for?
It indicates that a directory is a Python package.
How do I import from a package?
Use the dot notation, e.g., import package_name.module_name
.
How should I structure my modules and packages?
Organize related code into modules and group modules into packages based on functionality.
What naming conventions should I follow?
Use descriptive names for modules and packages.
How can I avoid circular imports?
Carefully structure your code to avoid dependencies that create circular import issues.
Can I have nested packages?
Yes, you can create hierarchical package structures.