Excel Spreadsheet Processing

Use openpyxl to read and write .xlsx files.

Quick Start

from openpyxl import load_workbook

wb = load_workbook("input.xlsx")
ws = wb["Sheet1"]

value = ws["A1"].value
ws["B2"] = 42
ws["C2"] = "=SUM(A2:B2)"

wb.save("output.xlsx")

Use this for direct cell edits, formula updates, and simple workbook changes.

Reading Data with pandas

import pandas as pd

df = pd.read_excel('file.xlsx')                          # First sheet
all_sheets = pd.read_excel('file.xlsx', sheet_name=None) # All sheets as dict

Common Pitfalls

• Cell indices are 1-based: ws.cell(row=1, column=1) is A1.
• data_only=True destroys formulas on save: Use a separate workbook object for reading calculated values.
• ws.max_row overcounts: May include formatted-but-empty rows. Scan the column to find the last non-empty cell when you need the true data range.