> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Adding Src Directory
> This article explains how to restructure a FastAPI project by moving the main file into an "app" directory for better code organization.
In this lesson, we will adjust the project structure to improve code organization by moving the main file into a dedicated folder named "app". This change groups all application-specific code in one place and simplifies package management.
## FastAPI Endpoint for Updating a Post
Below is an example of a FastAPI endpoint for updating a post. Notice that this code sample is presented only once for clarity:
```python theme={null}
@app.put("/posts/{id}")
def update_post(id: int, post: Post):
index = find_index_post(id)
if index is None:
raise HTTPException(
status_code=status.HTTP_404_NOT_FOUND,
detail=f"Post with id: {id} does not exist"
)
post_dict = post.dict()
post_dict['id'] = id
my_posts[index] = post_dict
return {"data": post_dict}
```
## Sample Console Output
The following snippet shows a sample of the console output you may see when making requests to the API:
```plaintext theme={null}
INFO: 127.0.0.1:63024 - "GET /posts HTTP/1.1" 200 OK
INFO: 127.0.0.1:60784 - "PUT /posts HTTP/1.1" 200 OK
INFO: 127.0.0.1:60785 - "GET /posts HTTP/1.1" 200 OK
```
## Restructuring the Project
We are now creating a new folder named **app** to store our main application file. In Python, a folder can be used as a package if it contains an `__init__.py` file.
Even though the `__init__.py` file can be empty, its presence is essential as it signals to Python that the folder should be treated as a package.
After creating the **app** folder and adding an `__init__.py` file inside it, move the main file into the **app** directory. At this point, you'll encounter an error because the startup command is still referencing the main file from the base directory.
## Updating the Startup Command
Previously, the application was launched using a command similar to:
```plaintext theme={null}
(venv) C:\Users\sanje\Documents\Courses\fastapi>uvicorn main:app --reload
```
In this command, **main** referred to the file in the project’s base directory. Now that the main file has been moved into the **app** package, the startup command must be updated to indicate the new package location:
```plaintext theme={null}
(venv) C:\Users\sanje\Documents\Courses\fastapi>uvicorn app.main:app --reload
```
This updated command directs Uvicorn to search for the file named **main** within the **app** folder and then use the FastAPI instance (named **app**) defined therein.
## Main File Code Snippet
Below is a snippet from the main file for clarity:
```python theme={null}
from typing import Optional
from fastapi import FastAPI, Response, status, HTTPException
from fastapi.params import Body
from pydantic import BaseModel
from random import randrange
app = FastAPI()
```
## Running the Application
After starting the application with the updated command, you might see output similar to the following:
```plaintext theme={null}
(venv) C:\Users\sanje\Documents\Courses\fastapi>uvicorn app.main:app --reload
INFO: Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO: Started reloader process [21236] using watchgod
INFO: Started server process [4760]
INFO: Waiting for application startup.
INFO: Application startup complete.
127.0.0.1:50834 - "GET /posts/1 HTTP/1.1" 200 OK
```
## Verifying the Endpoint
Finally, test the endpoint for retrieving an individual post. For example, a GET request to the endpoint might return a JSON response similar to this:
```json theme={null}
{
"post_detail": {
"title": "title of post 1",
"content": "content of post 1",
"id": 1
}
}
```
Everything should now function as expected. This new structure will help keep your application code well-organized as you continue development.