Python · Theory

openpyxl

Theory

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openpyxl is about tabular files. csv is in the stdlib. Excel usually needs openpyxl or pandas. Always with open(...) so the file closes.

For openpyxl read: csv.reader or DictReader (column names). Write: writer / DictWriter. Don’t load a 2 GB file into memory if you can stream rows.

openpyxl on the board — one row name,marks → Asha,90. Print it back. Same idea for Excel cells.

openpyxl — output — Asha 90. Cell A1 is that value.

Exam tip

stdlib csv vs Excel library. One sentence + tiny row example.

# openpyxl
print("Asha", 90)
# wb = Workbook(); ws['A1']='Asha'; wb.save('marks.xlsx')

openpyxl — output: Asha 90. Cell A1 is that value.