Data handling turns a stored dataset into useful information by reading, selecting, combining, sorting, and displaying records. A practical workflow separates the input file, the processing steps, and the output. section 2.8.2
A beginner-friendly workflow uses:
- Input: inspect a CSV file, its header row, columns, commas, and rows. section 2.8.2
- Process: read the file with Python, filter records by position, and add passing-yard totals for each player. section 2.8.2
- Output: sort the totals from highest to lowest and print the selected players. section 2.8.2
NFL quarterback statistics
An NFL offensive-statistics CSV can be processed to find quarterbacks with the greatest combined passing yards. The output lists Patrick Mahomes, Tom Brady, Aaron Rodgers, Josh Allen, and Derek Carr; changing the instruction then removes Tom Brady from the printed results. section 2.8.2
Figure 2.5 The first few columns and rows of the nfl_offensive_stats.csv dataset
Use the dataset preview to connect CSV columns and rows with the later filtering, aggregation, and ranking steps. section 2.8.2

