How to use the ocflib.account.search function in ocflib

"""Verifies whether a given CalLink OID is eligible for a new OCF account.

    Checks that:
      - User doesn't already have an OCF account
        Issues a warning which staff can override if they do (unlike
        validate_calnet_uid, which issues an error).

    OID `0` can create an infinite number of accounts; we use this for
    department-sponsored groups and others without CalLink OIDs.
    """

    if oid == 0:
        return

    # check for existing OCF accounts
    existing_accounts = search.users_by_callink_oid(oid)

    if existing_accounts:
        raise ValidationWarning(
            'CalLink OID already has account: ' + str(existing_accounts))

def get_calnet_names(uid):
    """Returns CalNet LDAP entries relating to names"""

    attrs = search.user_attrs_ucb(uid)
    if attrs:
        return {key: attrs[key]
                for key in ('givenName', 'sn', 'displayName') if key in attrs}

def validate_username(username, realname):
    """Validates a username and realname pair to ensure:

    * Username isn't already in use
    * Username is based on realname
    * Username isn't restricted."""

    if search.user_exists(username):
        raise ValidationError('Username {} already exists.'.format(username))

    try:
        validators.validate_username(username)
    except ValueError as ex:
        raise ValidationError(str(ex))

    SIMILARITY_THRESHOLD = 2

    if similarity_heuristic(realname, username) > SIMILARITY_THRESHOLD:
        raise ValidationWarning(
            'Username {} not based on real name {}.'.format(username, realname))

    if any(word in username for word in BAD_WORDS):
        raise ValidationWarning('Username {} contains bad words.'.format(username))