<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def values_from_env(env_prefix, settable, booleans, repeatable):
 """Get all values from environment variables. :param str env_prefix: Argument from docoptcfg(). :param iter settable: Option long names available to set by config file. :param iter booleans: Option long names of boolean/flag types. :param iter repeatable: Option long names of repeatable options. :return: Settable values. :rtype: dict """

    defaults_env = dict()
    for key in settable:
        try:
            defaults_env[key] = get_env(key, env_prefix, key in booleans, key in repeatable)
        except KeyError:
            pass
    return defaults_env