# How to Generate a JSON Report Filename from an Uploaded File in Python

This Python code creates a new filename for a report using the name of an uploaded file. It automatically removes the original file extension and adds `_report.json` to the filename.

## 1\. The Code

```python

output_filename = (
    f"{uploaded_file.name.rsplit('.', 1)[0]}_report.json"
)
```

## 2\. Understanding Each Part

a. `uploaded_file.name`\
\
The `name` property provides access to the original name of the uploaded file.

---

b. `.rsplit('.', 1)`

Separates the filename from its extension.

- `rsplit()` – splits a string from right to left. Python starts looking from the right-hand side of the string and finds the first period it encounters.
- `'.'` – tells Python to use the period as the separator.
- `1` – tells Python to perform only one split.

For example, Python looks at the filename `data.pdf` and splits it at the last period.

The period separates two things:

- `data` – the filename
- `pdf` – the file extension

If you run this code:

```python
"data.pdf".rsplit('.', 1)
```

The result is:

`['data', 'pdf']`

---

c. `[0]`

Selects the first element of the resulting list, which contains the filename without its extension.

Output:

`data`

---

d. `f"..._report.json"`

An f-string allows us to insert the extracted filename into a new string.

The `_report.json` suffix is added to create the final report filename.

---

e. `output_filename`

Stores the generated filename in the `output_filename` variable so it can be used later in the program.

## Example in Action

Suppose a user uploads a file named:

`data.pdf`

The code processes the filename as follows:

1. **Original filename:** `data.pdf`
2. **Remove extension:** `data`
3. **Add suffix:** `_report.json`
4. **Final filename:** `data_report.json`

This approach is useful because it:

1. **Automates naming:** No need to manually create report filenames.
2. **Preserves context:** The report keeps the original uploaded file's name.
3. **Removes the original extension:** Prevents filenames such as *monthly_sales.csv_report.json*.

The main purpose of this code is to dynamically generate a JSON report filename based on the original uploaded file.

- **Uploaded file:** `data.pdf`
- **Generated file:** `data_report.json`