Rhinoscript snippet to batch convert all ascii stl files to binary stl files in a selected folder.

convertToBinary.py

import rhinoscriptsyntax as rs
from os import listdir
from os.path import isfile, join

folder = rs.BrowseForFolder()

if folder is not None:
    files = [f for f in listdir(folder) if isfile(join(folder, f))]
    for file in files:
        f = file.split('.')
        if len(f) == 2 and f[1] == 'stl':
            filepath = join(folder, file)
            filepath = '"' + filepath + '"'
            rs.Command("-_Import " + filepath + " _Enter")
            rs.Command("_Flip")
            
            rs.Command('-_Export "' + join(folder,f[0]+'-b.stl') + '" _Enter') 
            
            rs.Command('_SelAll')
            rs.Command('_Delete')