How to quickly make the contents of all files in a folder lowercase?

Question

linux

Subject.
There is a folder with tons of files, <130kb each.
You need to quickly bypass them all and make them in lower case.
As an option, write a Python script, but the fastest option is still interesting.

Answer 1

import sys

filename = sys.argv[1]
with open(filename, "r+") as f:
    data = f.read()
    f.truncate()
    f.seek(0)
    f.write(data.lower())

in short, I already did it myself)

Answer 2

I don’t know about thousands, but just convert to lowercase:

#!/bin/bash
cd <ваша папка>
files=`find | sed 1d`
for f in $files; do
   #echo mv $f "${f,,}"
   mv $f "${f,,}"
done