Sales Data Cleaning Task

I have a raw export of sales transactions that needs to be transformed into an analysis-ready dataset. The file suffers from duplicate rows, inconsistent date and currency formats, occasional missing values, and a few obvious entry errors. Your mission is to clean, standardise, and validate every record so I can trust the numbers before they flow into our reporting dashboards.

Please outline a detailed project proposal in your bid. I want to understand the specific techniques and tools you will apply—whether that is Excel Power Query, Python with pandas, SQL, or another approach—as well as the checkpoints you will use to confirm the work is accurate.

Deliverables
• Cleaned sales dataset in the original file format (CSV)
• A concise changelog or script that documents every transformation step
• Brief summary of data quality issues discovered and how they were resolved

Acceptance criteria
• No duplicate transaction IDs
• Dates in YYYY-MM-DD format and currencies in a single, agreed unit
• Critical fields (item, quantity, price, total, date) are complete and correctly typed
• All cleaning steps reproducible through the supplied script or documented procedure

Confidentiality is essential, so the file will be shared once we agree on the workflow and timeline. I look forward to reading your proposal and seeing how you plan to bring this dataset up to standard.