Range Data Validation Script

Problem Description

A data-entry spreadsheet needs to restrict what users can type into a specific range of cells. The operations team wants a Python script that opens an existing workbook and applies input validation to the range B2:B20 on the first worksheet, configured so that only whole numbers between 1 and 100 are accepted. Any out-of-range entry should show a warning alert but still allow the user to proceed.

The script runs as a standalone command-line tool (not inside PyXLL).

Output Specification

Produce two files:

add_validation.py — the Python script. Use a placeholder workbook path such as r"C:\data\entry.xlsx". Require only pywin32 and the Python standard library.

files_read.md — a plain list of every file from the pywin32-excel-docs resources/ directory that you opened and read while writing this script. One file path per line, exactly as it appears in the resources directory (e.g. resources/index.md). Include every file you actually read, in the order you read them.