What does import from do in Python?

Jacob 48 Published: 08/04/2024

What does import from do in Python?

I'm happy to respond in English!

In Python, the import statement is used to load a module into the current namespace. A module is a file that contains Python code and can be reused across multiple programs.

When you use the import statement, you are essentially copying the definitions (functions, variables, classes, etc.) from another module into your current script. This allows you to reuse code written in one module within another.

Here's a simple example:

# mymodule.py

def greet(name):


print(f"Hello, {name}!")

main.py

import mymodule


mymodule.greet("John")  # Output: Hello, John!

In this example, the main.py script imports the mymodule module and then calls its greet function with the argument "John".

There are several ways to import modules in Python:

Absolute Import: This is the most common way to import a module. You specify the full path to the module, including the file name: 
    import mymodule
Relative Import: If you're working with multiple modules within a single package (directory), you can use relative imports to access them: 
    from . import mysubmodule
Wildcard Import: You can import all definitions from a module using the * wildcard: 
    from mymodule import *
Module Aliases: Sometimes, you might need to use multiple modules with similar names. In this case, you can create an alias for one of them: 
    import math as mymath
Importing Specific Definitions: If you only want to access specific definitions from a module (like functions or variables), you can use the from keyword: 
    from mymodule import greet, PI

Python also supports several other features related to importing modules:

Aliasing Modules: You can rename imported modules using the as keyword. Importing Multiple Modules: You can list multiple modules to be imported in a single line of code: 
    import math, statistics
Using Wildcards with Aliases: When using wildcards, you can also specify aliases for the imported modules: 
    from mymodule import *, math as mymath

Remember to keep your module names consistent and descriptive, so it's easy to understand what each module is intended for.

In summary, Python's import statement allows you to load definitions (functions, variables, classes, etc.) from other modules into your current script. This enables code reuse, makes maintenance easier, and helps organize complex programs.

What is the difference between import and from in python using

I'm glad you asked!

In Python, import and from are two related but distinct ways to bring external modules or packages into your code. Understanding their differences is crucial for effective module management.

Import

When you use the import statement, you're telling Python to load an entire module (a file containing Python code) into memory. This process is often referred to as "importing" the module. The imported module becomes a separate object in your program's namespace, which can be accessed by its name.

For example:

import math

In this case, the entire math module (which contains various mathematical functions) is loaded into memory and made available for use in your code.

From

The from statement is used to import specific objects (functions, variables, classes, etc.) from a module. This process is often referred to as "importing" or "fetching" those specific objects. The imported objects become part of your program's namespace and can be accessed by their names.

For example:

from math import sin, cos

In this case, only the sin and cos functions from the math module are loaded into memory and made available for use in your code.

Key differences

Here are the key differences between import and from:

Entire module vs. specific objects: import loads an entire module, while from imports specific objects from a module. Namespace inclusion: When you use import, the imported module becomes part of your program's namespace. With from, only the imported objects are added to the namespace. Imported names: When using import, you typically refer to the imported module by its name (e.g., math.pi). With from, you can use the shorter, more specific names for the imported objects (e.g., sin() instead of math.sin()).

When to use each

Here are some general guidelines on when to use import and when to use from:

Use import when: You need access to an entire module's functionality. You want to refer to the imported module by its name (e.g., math.pi). The module is relatively small, and you don't mind loading the whole thing into memory. Use from when: You only need specific objects or functions from a module. You want to use shorter, more specific names for those objects (e.g., sin() instead of math.sin()). The module is large, and you don't want to load the entire thing into memory unless necessary.

In summary, import loads an entire module into memory, while from imports specific objects from a module. Understanding the differences between these two statements will help you effectively manage your Python code and avoid potential issues or inefficiencies.

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