mv renaming files deleted it

if i had a playlist filled with music, i would want it to shuffle and play because i wouldn't want to hear the same song order over and over again as it gets old real fast.. same thing here but with pictures

so i wanted my files randomized and i looked up a command to randomize file names and i got this

for file in *.jpg; do
mv -- "$file" "$RANDOM-$RANDOM-$RANDOM.jpeg"
done

it worked well but the problem was that it only changed jpeg so i did this

for file in *.jpg; do
mv -- "$file" "$RANDOM-$RANDOM-$RANDOM.jpeg"
done

for file in *.jpeg; do
mv -- "$file" "$RANDOM-$RANDOM-$RANDOM.jpg"
done

for file in *.JPG; do
mv -- "$file" "$RANDOM-$RANDOM-$RANDOM.png"
done

i ran this command as a shell script and it removed all files from the folder. And no where to be found. i also ran it in a removable disk

EDIT:

It just turned out to be a visual glitch and a power outage fixed it.

The reason why i took so long to edit this is cause my boot got corrupted and it took really long to fix it.

Thanks to anyone who tried to help.

You can utilize the Python programming language for this very easily:

import glob
import random

# reads in from the current folder the files with the pattern *.mp3 and assign it to a variable of type list.
music_files = glob.glob("*.mp3")

# is picking randomnized a file from the variable.
random_music_file = random.choice(music_files)

Python is installed up front on each Ubuntu installation.

To possibly locate your files, with five digits and a dash in the name, with a name end with jpg:

First do
$ sudo updatedb - to freshen the database... then
$ locate --regex "[0-9]{5}-.*jpg$"

Oh, and prior to those you need e.g.
$ sudo apt install mlocate - if you haven't already done it.

One more thing: if PRUNEPATHS= in /etc/updatedb.conf happens to contain the path where the files are, they won't be shown.