def get_help(module_name):
    modules_copy = sys.modules.copy()
module = __import__(module_name)
h = help(module)
for modname in list(sys.modules):
    if modname not in modules_copy:
        del sys[modname]
if sys.getrefcount(module) > 1:
    warnings.warn('Module {} is likely not to be completely wiped'.format(
        module_name))
del module
return h
get description of an installed package without actual importing it