815 messy customer records cleaned to 725 usable rows in Python by Sabin Mainali815 messy customer records cleaned to 725 usable rows in Python by Sabin Mainali

815 messy customer records cleaned to 725 usable rows in Python

Sabin Mainali

Sabin Mainali

This is a self-directed demo, not client work. I wrote a Python pipeline with pandas that took a messy customer list of 815 rows and returned 725 clean records. It merged 54 duplicate rows and held 36 rows for review, each with a stated reason. No value was guessed.

What was the problem?

Customer lists collect duplicates and broken values over time. A list in that state cannot go straight into a CRM or an email tool. Someone has to decide which rows are the same customer and which values can be trusted.

What did I build?

A Python script using pandas. It reads the messy CSV file, merges duplicate customer records and sets aside every row it cannot fix with confidence. Each held row gets a written reason, so a person can decide quickly.

How did I check the output?

Every input row is accounted for: 725 clean + 54 merged + 36 held = 815.
A row the script could not fix was held back with a reason, not filled with a guess.

What was the result?

815 rows in, 725 clean records out.
54 duplicate rows merged into the records they matched.
36 rows held for review, each with a stated reason.

What would this look like for your business?

Send me your messy CSV or Excel file. I merge duplicate records on a key you choose, fix inconsistent dates, casing and text, handle missing or malformed values and clean up the columns. You get the cleaned file, a short summary of what changed and a separate list of any records that need your decision. I never guess a value to fill a gap. The package covers up to about 5,000 rows. That is my "I will clean and organize your CSV or Excel data" service, from $30 on Contra.
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Posted Aug 20, 2026

Self-directed demo. A pandas pipeline turned 815 messy customer rows into 725 clean records, merged 54 duplicates and held 36 for review with a reason.