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

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:

"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