FREE Data Analyst Course: Excel learning resource
FREE Data Analyst Course
Broader playlist that places Excel cleaning inside an end-to-end data analyst learning path. Watch this playlist from Chandoo and use it to practice Power Query cleanup and Remove duplicates and blanks.
Why this resource is useful
Broader playlist that places Excel cleaning inside an end-to-end data analyst learning path.
What to practice while watching
- Power Query cleanup
- Remove duplicates and blanks
- Split and combine columns
Recommended learning path
Start by watching the lesson once without pausing, then reopen Excel and rebuild the example with your own small dataset. Save one clean practice workbook before moving to the next topic.
Source details
- Channel: Chandoo
- Format: playlist
- Level: Mixed
- Topic: Data Cleaning
Go deeper with this skill
Turn messy imported data into a reliable table that formulas, pivots, and reports can use safely. For this article, the goal is to practice: Broader playlist that places Excel cleaning inside an end-to-end data analyst learning path. Watch this playlist from Chandoo and use it to practice Power Query cleanup and Remove duplicates and blanks.
Practice workbook setup
Copy messy sample data to a raw-data sheet and keep the original untouched while you clean a separate working copy.
Practice workflow
- Identify the expected columns and data types before changing anything.
- Remove obvious blanks and duplicates, then check whether any removals need business approval.
- Standardize spacing, casing, dates, and number formats.
- Create a small before-and-after table so the cleanup can be reviewed.
Quality checks
- The row count before and after cleanup is explainable.
- Key columns have no unexpected blanks.
- Dates, IDs, and amounts are stored as the correct data type.
Common mistakes
- Cleaning directly over the only copy of the data.
- Removing duplicates without deciding which columns define a duplicate.
- Fixing visible rows while hidden filtered rows stay messy.
Next actions
- Convert the cleaned range into an Excel Table.
- Repeat the same cleanup with Power Query if the data will arrive again.
Formula focus: even if this workflow is not formula-heavy, add one check cell that confirms the final output still matches the source data.
