CSV Header Handling: Missing Headers, Duplicates, and Mapping Fields
Fix CSV header problems: missing first rows, duplicate column names, whitespace, and BOM characters that break parsers silently.
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Tags: data, csv, parsing
CSV Header Handling: Missing Headers, Duplicates, and Mapping Fields Headers are the skeleton of a CSV file. When they're clean, the rest of the conversion is straightforward. When they're missing, duplicated, or inconsistently formatted, they cause silent data corruption and hard-to-debug downstream failures. This guide covers every common header problem — and the exact code to fix each one. Duplicate Column Names Duplicate headers cause silent data loss. When you have two columns named , the second one overwrites the first in any dict-based parser. After parsing: — the first date is gone. Detecting duplicates Renaming duplicates automatically Append a numeric suffix to disambiguate: Input: Output headers: JavaScript version: --- Whitespace in Headers and and are three different JSON…
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