84 articles tagged #Data Analysis
Your INDEX MATCH formula looks right, but sorted data is feeding it wrong results. This guide breaks down the exact reason it happens and shows you the precise fix — no helper columns needed.
INDIRECT is powerful for dynamic references, but one wrong character in the sheet name and you get a #REF! error that's maddeningly hard to debug. Here's exactly what causes it and how to fix it for good.
Your SUMIFS formula looks right, but the moment you point a criteria range or criteria value at another sheet, it returns zero. Here's why that happens and exactly how to fix it.
TEXTJOIN returning an empty string when your range contains blank cells is one of Excel's more confusing silent failures. Here's exactly why it happens and how to fix it without restructuring your data.
Your COUNTIF formula looks right, but the count is off when you use wildcards. Learn exactly why asterisks and question marks mislead COUNTIF — and how to fix every common case.
Your SUMIFS total looks suspiciously high and you can't figure out why. Misaligned sum and criteria ranges are the most common culprit — and Excel won't warn you. Here's how to diagnose and fix it.
IFERROR is supposed to be a safety net, but wrap it around the wrong formula and it silently swallows genuine mistakes while handing you bad data. Here's how to diagnose the problem and fix it properly.
Reshaping data with Pandas melt() and stack() is a common task in analytics pipelines, but many developers are surprised when the resulting dataset contains duplicate rows, inflated record counts, or incorrect aggregations. Learn why these issues occur and how to avoid them.
Writing datetime objects with xlsxwriter and getting ugly floats like 45123.708333 instead of a readable date? Here's why it happens, what the format object actually does, and how to fix it for good.
You set up data validation dropdowns in xlsxwriter, added sheet protection, opened the file in Excel — and the dropdowns are gone. Here's exactly why that happens and how to fix it without losing your protection settings.
You've called freeze_panes on every sheet, but when the file opens in Excel only some sheets are frozen—or none at all. Here's exactly why xlsxwriter silently drops the setting and how to fix it for good.
If your Pandas pivot_table is producing numbers that don't match your expectations, the aggregation is probably running on the wrong columns. Here's how to catch it, understand why it happens, and fix it for good.