Return module from `mod_name`.

def import_mod(mod_name:str, ignore_errors=False):
    "Return module from `mod_name`."
    splits = str.split(mod_name, '.')
    try:
        if len(splits) > 1 : mod = importlib.import_module('.' + '.'.join(splits[1:]), splits[0])
        else: mod = importlib.import_module(mod_name)
        return mod
    except:
        if not ignore_errors: print(f"Module {mod_name} doesn't exist.")