def user_edit(fn, t):

    nmini = 11
    if re.search(r'(specular|varia)', fn):
        nmini = 50

    m = re.search(r'bp\.parse_args\(sim_n=(\d+)', t)
    if not m:
        return t
    n = m.group(1)
    t = re.sub(r"bp\.simargs\['n'\]", f'<%= sm ? {nmini} : {n} %>', t)

    t = re.sub(r'(bp\.parse_args\()sim_n=(\d+),\s*', r'\1', t)
    t = re.sub(r'(bp\.parse_args\()sim_n=(\d+)\)', r'\1)', t)

    if not re.search(r'^#!/usr/bin/env python3\n', t):
        raise Exception("missing shebang in "+fn)
    t = re.sub(r'(^#!.*?\n("""\n(.*\n)+"""\n)?)\n*',
               r'\1'+'<% sm = (e=ENV["SHORTMODE"] and e!="OFF") %>\n', t)

    return t