Open a doc from terminal, but not by its name

You probably haven't discovered Tab-completion (see here) yet.

While typing a filename in Terminal just type a first few letters and hit Tab and see magic!

Just for fun, literally answering the question:

#!/usr/bin/env python3
import os
import subprocess

show_hidden = False

currfiles = os.listdir("./")
if not show_hidden:
    currfiles = [f for f in currfiles if not f.startswith(".")]
n = 1
for f in currfiles:
    print(str(n) + ". " + f)
    n = n + 1

picked = int(input("Quick, quick, give me a number:\n"))
subprocess.run(["xdg-open", currfiles[picked - 1]])

How it works in practice

1. In terminal, in the working dir, run "o" (as a command)

2. The content of the current directory is listed, numbered. Pick the number and the item is opened:

   

Set up

...is easy:

1. Create, if it doesn't exist yet, a folder named "bin" in your home directory
2. Copy the script into an empty file, save it as (literally) "o" (no extension), and make it executable

3. Log out and back in and start using the command by just typing

   $ o
   

   in terminal

N.B.

If you'd like to show hidden files as well, change

show_hidden = False

into:

show_hidden = True

There is a little-known feature in Bash that allows you to do this without calling on python or any other third-party tool, and with a single line:

select file in *; do open "$file"; break; done