Python Virtual Environments

 Python Virtual Environments:

  • Isolated python environment for development where you can have your own packages without disturbing other projects or applications as these packages or settings are native to your isolated development environment.
  • It means you can do development for webpage through FastAPI in one environment, A.I in another environment and Internet of Things on another environment.
  •  It helps to make all applications independent and non interfering with each other.

Installation of Dependencies:

  • Pip is the Python package manager.
    • Pip is used to install and update packages.
    • You will want to make sure you have the latest version of pip installed.
    • commands
      • python -m pip --version -> will provide version of pip present with your python version in your machine.

Setting up virtual environment:

  • Create a brand new folder for your project as empty location.
  • check pip for dependencies already installed.
  • Use python as it already have dependencies to use/create virtual environments called venv.
  • Create new FastAPI environment as a virtual environment.
  • Activating our virtual environment to install or dependencies in.

Commands and Virtual environment setup for Fast API:(Windows steps)

step 1: 

C:\Users\punee>pip list
Package           Version
----------------- --------
annotated-types   0.7.0
anyio             4.9.0
fastapi           0.115.12
idna              3.10
mangum            0.19.0
pip               25.0.1
pydantic          2.10.6
pydantic_core     2.27.2
sniffio           1.3.1
starlette         0.46.1
typing_extensions 4.12.2

step 2:

C:\Users\punee\OneDrive\Desktop>mkdir virtualenvFastapi

step 3:

C:\Users\punee\OneDrive\Desktop>cd virtualenvFastapi

step 4:

C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>python -m venv fastapienv

It will create the virtual ennvironment directory with necessary files with name of directory as fastapienv.

step 5:

C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>fastapienv\Scripts\activate.bat

It will activate the virtual environment over the empty folder where you have created the virtual environment.

Verification of activation:
(fastapienv) C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>

As in your directory structure you can see at start their is fastapienv written, it is proof of activation.

step 6:

(fastapienv) C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>pip list
Package Version
------- -------
pip     24.3.1

It will show list of tools installed in virtual environment.

step 7:

Install fastapi and "uvicorn[standard]" in virtual environment.
or use : pip install -r .\requirement.txt

(fastapienv) C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>pip install fastapi
It will install fastapi packages in your python local venv as library packages.

To verify installation.
(fastapienv) C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>pip list
Package           Version
----------------- --------
annotated-types   0.7.0
anyio             4.9.0
fastapi           0.115.12
idna              3.10
pip               25.1.1
pydantic          2.11.5
pydantic_core     2.33.2
sniffio           1.3.1
starlette         0.46.2
typing_extensions 4.13.2
typing-inspection 0.4.1



(fastapienv) C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>pip install "uvicorn[standard]"

To verify installation.
(fastapienv) C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>pip list
Package           Version
----------------- --------
annotated-types   0.7.0
anyio             4.9.0
click             8.2.1
colorama          0.4.6
fastapi           0.115.12
h11               0.16.0
httptools         0.6.4
idna              3.10
pip               25.1.1
pydantic          2.11.5
pydantic_core     2.33.2
python-dotenv     1.1.0
PyYAML            6.0.2
sniffio           1.3.1
starlette         0.46.2
typing_extensions 4.13.2
typing-inspection 0.4.1
uvicorn           0.34.2
watchfiles        1.0.5
websockets        15.0.1


step 8: to deactivate the virtual environment use.

(fastapienv) C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>deactivate

Validation step:
C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>pip list
Package           Version
----------------- --------
annotated-types   0.7.0
anyio             4.9.0
fastapi           0.115.12
idna              3.10
mangum            0.19.0
pip               25.0.1
pydantic          2.10.6
pydantic_core     2.27.2
sniffio           1.3.1
starlette         0.46.1
typing_extensions 4.12.2

C:\Users\punee\OneDrive\Desktop\virtualenvFastapi>

You will not be able to see uvicorn installed in your global packages and others which you have installed only in your virtual environment.


If you are having issue with power-shell terminal in windows (VSCode) and not able to execute activate command then follow below commands they will help:
PS C:\Users\punee\OneDrive\Desktop\virtualenvFastapi> GET-ExecutionPolicy
Restricted
PS C:\Users\punee\OneDrive\Desktop\virtualenvFastapi> GET-ExecutionPolicy -List

        Scope ExecutionPolicy
        ----- ---------------
MachinePolicy       Undefined
   UserPolicy       Undefined
      Process       Undefined
  CurrentUser       Undefined
 LocalMachine       Undefined


PS C:\Users\punee\OneDrive\Desktop\virtualenvFastapi> SET-ExecutionPolicy RemoteSigned -Scope CurrentUser
PS C:\Users\punee\OneDrive\Desktop\virtualenvFastapi> GET-ExecutionPolicy
RemoteSigned

PS C:\Users\punee\OneDrive\Desktop\virtualenvFastapi> .\fastapienv\Scripts\activate
(fastapienv) PS C:\Users\punee\OneDrive\Desktop\virtualenvFastapi> deactivate
PS C:\Users\punee\OneDrive\Desktop\virtualenvFastapi> 

Comments

Post a Comment

Popular posts from this blog

Post Request with Pydantic usage (input validator)

Image
Post Request by using Pydantic Pydantic Python library that is used for data modeling, data parsing and has efficient error handling. Pydantics is commonly used as a resource for data validation and how to handle data coming to our FastAPI application. Pydantic implementation mechanism Create a different request model for data validation Field data validation on each variable/element BaseModel is the Pydantics BaseModel class which will provide facility to validate data. Field is the keyword to do it. As it will help to provide constraints for data validation. sample class BookRequest(BaseModel):     id: int = Field(gt=0)     title: str = Field(min_length=3)     author: str = Field(min_length=1)     description: str = Field(min_length=1, max_length=100)     rating: int = Field(gt=0, lt=5) Book Request and Book Conversion We will convert the Pydantic Request into a Book Example for post request method @app.post("/create_book") async def c...
Read more

Code Scalability and Routing

Image
 Creating Authentication file As we need to keep authentication part separate from our main application working so that we will not mess-up with our main application logic and it's security settings and authentication criteria as well as logics. auth.py - Basic authentication code stub. # This file is to define authenticator and authorization for the Todo application. from fastapi import FastAPI , status app = FastAPI () @ app . get ( "/auth" , status_code = status . HTTP_200_OK ) async def get_user ():     return { 'user' : 'authenticated_user' } Create Routers Package Here we want to use both and auth.py and main.py file to run together and to allow routers to run smoothly and want to scale the project code. To make this possible we need to use router facility or FastAPI. Here we are going to have a main file is a route of our application and routes will sit on this main file and will help in performing the tasks on call from main file. To make i...
Read more

CRUD Assignment

Image
 CRUD Assignment 1. Create a new API Endpoint that can fetch all books from a specific author using either Path Parameters or Query Parameters. Code and Result: As async is implemented by FastAPI itself hence ignored it. from fastapi import FastAPI app = FastAPI () BOOKS = [         { "title" : "Book One" , "author" : "Author A" , "category" : "Fiction" },         { "title" : "Book Two" , "author" : "Author B" , "category" : "Non-Fiction" },         { "title" : "Book Three" , "author" : "Author A" , "category" : "Biography" },         { "title" : "Book Four" , "author" : "Author A" , "category" : "Historical" },         { "title" : "Book Five" , "author" : "Author A" , "category" : "Romanc...
Read more