A Python script that converts the JPEG and PNG pictures of your site to light WebP files in one run

Example result

python merge_sales.py --month 2026-10

2026-11-02 09:14:03 INFO  Folder: sales/2026-10, 9 files found
2026-11-02 09:14:03 INFO  shop-01.csv: 1,284 rows
2026-11-02 09:14:04 INFO  shop-02.xlsx: 967 rows
2026-11-02 09:14:04 WARN  shop-07.csv: 3 rows without a price skipped (lines 88, 412, 913)
2026-11-02 09:14:05 INFO  Done: 10,412 rows -> report-2026-10.xlsx (sheets "Sales" and "Totals")

[columns]
date = Date, Sale date, Day
product = Product, Item, Name
quantity = Qty, Quantity, Pcs
price = Price, Unit price

def read_shop_file(path: Path, columns: dict[str, list[str]]) -> pd.DataFrame:
    """Reads one shop's file and gives it the report's column names."""
    table = pd.read_excel(path) if path.suffix == ".xlsx" else pd.read_csv(path, encoding="utf-8-sig")
    renamed = {}
    for name, variants in columns.items():
        found = next((c for c in table.columns if c.strip() in variants), None)
        if found is None:
            raise ReportError(f"{path.name}: no column for '{name}' (looked for {', '.join(variants)})")
        renamed[found] = name
    table = table.rename(columns=renamed)[list(columns)]
    table["shop"] = path.stem
    return table

About this service

WebP pictures are usually noticeably lighter than JPEG or PNG at a similar look, so pages load faster. This Python script converts the pictures in a folder, such as your site's uploads folder copied to your computer, into WebP: photos with the quality you choose, logos and graphics with transparency kept or without any loss. It keeps the folder layout and file names, skips pictures already converted and, from Standard, writes how much space each file saved. Send us the folder layout and a few sample pictures. You run the script yourself on your computer or server. It makes the files; pointing your site's pages to them (or a plugin that does it) is a separate step the README explains.

What is included

• What you getA ZIP archive with the Python script, a README with step-by-step instructions and, from Standard, a settings file with folders and quality; the code is also shown on the order page.
• JPEG and PNG inAlso GIF and BMP without animation
• Transparency keptLogos and icons stay clean on any background
• Same names and foldersphoto.jpg becomes photo.webp in the same place
• Originals keptNothing is deleted or overwritten
• Readable codeWith comments, easy to change quality later

How it works

1. 1
   TaskYou describe the folders and send a few sample pictures
2. 2
   CodeWe write the script and the guide to running it
3. 3
   Try itYou convert a copy of the folder and compare the pictures
4. 4
   ChangesYou ask for changes within your package and send any error message

What we need from you

Where the pictures are (a folder on your computer, or a folder on your server you can reach yourself), roughly how many there are and of what kinds: photos, logos, screenshots. Whether WebP files should sit next to the originals or in a separate folder, the quality you want or a sample picture to judge by, and what your site runs on, if it matters for the file paths. Your system: Windows, macOS or Linux.

We will ask you:

• Where are the pictures?
• What kinds of pictures are they?
• Where should the WebP files go?
• Where will it run?

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Questions and answers

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