A Python script that tidies your own contact list: one format for names, phones and emails, and no duplicates

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

A contact list gathered over years from a shop, a CRM and spreadsheets ends up with the same person three times, phones written five ways and emails with spaces or typos. This Python script cleans your own list on your computer: trims spaces, fixes capital letters, writes phone numbers in one format, flags emails whose form is broken and finds duplicates by email or phone, then saves a clean file and a separate file of what it removed, so you can check it. Send us a few rows with made-up names, phones and emails that look like yours, and your rules. The list never comes to us, and the script never sends anything anywhere. It checks the form of an address, not whether the mailbox exists.

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 your cleanup rules; the code is also shown on the order page.
• Duplicates foundBy email, by phone or by the two together
• One phone formatWith the country code you set for numbers without one
• Removed rows keptA separate file with every removed or merged row
• Stays on your computerYour list is never uploaded or sent
• Readable codeWith comments, easy to change a rule later

How it works

1. 1
   RulesYou send made-up sample rows and your rules for duplicates
2. 2
   CodeWe write the script and the guide to running it
3. 3
   Try itYou run it on a copy of your list and look through the removed rows
4. 4
   ChangesYou ask for changes within your package and send any error message

What we need from you

The column names of your list and 10-20 rows with made-up names, phones and emails written the way they appear in your real data (with the same kinds of mess). Your rules: what counts as a duplicate, which row to keep (the newest, the fullest), the country code for local phone numbers and how phones should be written. CSV or Excel, and your system: Windows, macOS or Linux. Never send the real list.

We will ask you:

• Where does the list come from?
• What counts as a duplicate?
• Which row should stay?
• How should phones look?

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Questions and answers

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