Dtypes

dtypes are the data types assigned to columns in structured datasets. In Brevvie Python + AI — Section 3: Data, Polars & Pair Programming, checking dtypes is presented as one of the first things to do with any new dataset.

Examples from the source

• integer columns for counts or whole numbers
• float columns for decimal values
• string columns for text
• boolean columns for true/false filters
• date and datetime columns for time-aware analysis

Why they matter

The dtype determines which operations are valid. A numeric column accidentally loaded as String must be cleaned or cast before aggregation will work.