How to use the mongoengine.ListField function in mongoengine

"""Ensure that a list field only accepts lists with valid elements."""
        access_level_choices = (
            ("a", u"Administration"),
            ("b", u"Manager"),
            ("c", u"Staff"),
        )

        class User(Document):
            pass

        class Comment(EmbeddedDocument):
            content = StringField()

        class BlogPost(Document):
            content = StringField()
            comments = ListField(EmbeddedDocumentField(Comment))
            tags = ListField(StringField())
            authors = ListField(ReferenceField(User))
            authors_as_lazy = ListField(LazyReferenceField(User))
            generic = ListField(GenericReferenceField())
            generic_as_lazy = ListField(GenericLazyReferenceField())
            access_list = ListField(choices=access_level_choices, display_sep=", ")

        User.drop_collection()
        BlogPost.drop_collection()

        post = BlogPost(content="Went for a walk today...")
        post.validate()

        post.tags = "fun"
        self.assertRaises(ValidationError, post.validate)
        post.tags = [1, 2]

def test_default_value_is_not_used_when_changing_value_to_empty_list_for_dyn_doc(
        self
    ):
        """List field with default can be set to the empty list (dynamic)"""
        # Issue #1733
        class Doc(DynamicDocument):
            x = ListField(IntField(), default=lambda: [42])

        doc = Doc(x=[1]).save()
        doc.x = []
        doc.y = 2  # Was triggering the bug
        doc.save()
        reloaded = Doc.objects.get(id=doc.id)
        self.assertEqual(reloaded.x, [])

job.delete()
                except (mongoengine.errors.DoesNotExist, mongoengine.errors.FieldDoesNotExist):
                    pass

        super().delete(*args, **kwargs)


class Term(EmbeddedDocument):
    predicate = StringField()
    literals = ListField(StringField())


class Comparison(EmbeddedDocument):
    obj1 = ListField(StringField())
    comp = StringField()
    obj2 = ListField(StringField())


class CodedStep(ExtrovirtsDocument):
    name = StringField()
    display_name = StringField()
    coded_name = StringField()
    parameters = ListField(StringField())
    score = IntField()
    add = EmbeddedDocumentListField(Term)
    requirement_terms = EmbeddedDocumentListField(Term)
    requirement_comparisons = EmbeddedDocumentListField(Comparison)
    remove = EmbeddedDocumentListField(Term)
    deterministic = BooleanField()
    significant_parameters = ListField(IntField())
    bindings = DictField()
    source_hash = BinaryField()

from __future__ import unicode_literals

from mongoengine import BooleanField, StringField, ListField, ReferenceField, \
    CASCADE

from core.database import YetiDocument
from core.user import User


class Group(YetiDocument):
    enabled = BooleanField(required=True, default=True)
    groupname = StringField(required=True, unique=True)
    members = ListField(ReferenceField(User, reverse_delete_rule=CASCADE))
    admins = ListField(ReferenceField(User, reverse_delete_rule=CASCADE))

    SEARCH_ALIASES = {}

meta = dict(
            collection = 'Groups',
            allow_inheritance = False,
            indexes = [],
        )

    id = StringField(db_field='_id', primary_key=True)
    title = StringField(db_field='t')
    rules = ListField(EmbeddedDocumentField(ACLRule), db_field='r')
    join_rules = ListField(EmbeddedDocumentField(ACLRule), db_field='j', default=list)
    request_rules = ListField(EmbeddedDocumentField(ACLRule), db_field='q', default=list)

    join_members = ListField(ReferenceField(EVECharacter), db_field='jm', default=list)
    request_members = ListField(ReferenceField(EVECharacter), db_field='rm', default=list)
    requests = ListField(ReferenceField(EVECharacter), db_field='rl', default=list)
    request_members_names = ListField(StringField(), default=list)
    join_members_names = ListField(StringField(), default=list)
    creator = ReferenceField('User', db_field='c')
    modified = DateTimeField(db_field='m', default=datetime.utcnow)
    _permissions = ListField(ReferenceField(Permission), db_field='p')

    # Permissions
    VIEW_PERM = 'core.group.view.{group_id}'
    EDIT_ACL_PERM = 'core.group.edit.acl.{group_id}'
    EDIT_PERMS_PERM = 'core.group.edit.perms.{group_id}'
    EDIT_MEMBERS_PERM = 'core.group.edit.members.{group_id}'
    EDIT_REQUESTS_PERM = 'core.group.edit.requests.{group_id}'
    EDIT_TITLE_PERM = 'core.group.edit.title.{group_id}'
    EDIT_ID_PERM = 'core.group.edit.id.{group_id}'
    DELETE_PERM = 'core.group.delete.{group_id}'
    CREATE_PERM = 'core.group.create'

# -*- encoding: utf-8 -*-
import gzip
import mongoengine
from discograph.library.mongo.MongoModel import MongoModel


class Master(MongoModel, mongoengine.Document):

    ### MONGOENGINE FIELDS ###

    artists = mongoengine.EmbeddedDocumentListField('ArtistCredit')
    data_quality = mongoengine.StringField()
    discogs_id = mongoengine.IntField(unique=True, null=True, sparse=True)
    genres = mongoengine.ListField(mongoengine.StringField())
    main_release_id = mongoengine.IntField()
    release_date = mongoengine.DateTimeField()
    styles = mongoengine.ListField(mongoengine.StringField())
    title = mongoengine.StringField()

    ### MONGOENGINE META ###

    meta = {
        'indexes': [
            'discogs_id',
            'title',
            '$title',
            ],
        'ordering': ['+discogs_id'],
        }

display_name = StringField(required=True)
  # This is the owner of the case
  owner = StringField(required=True)
  # These are the names of all the collaborators that are allowed to view the
  # case, including the owner
  collaborators = ListField(StringField())
  assignee = ReferenceField('User')
  individuals = ListField(EmbeddedDocumentField(Individual))
  created_at = DateTimeField(default=datetime.now)
  updated_at = DateTimeField(default=datetime.now)
  suspects = ListField(ReferenceField('Variant'))
  causative = ReferenceField('Variant')
  synopsis = StringField(default='')
  status = StringField(default='inactive', choices=STATUS_ORDER)
  is_research = BooleanField()
  events = ListField(EmbeddedDocumentField(Event))
  comments = ListField(EmbeddedDocumentField(Event))

  # This decides which gene lists that should be shown when the case is opened
  default_gene_lists = ListField(StringField())
  clinical_gene_lists = ListField(EmbeddedDocumentField(GeneList))
  research_gene_lists = ListField(EmbeddedDocumentField(GeneList))

  genome_build = StringField()
  genome_version = FloatField()

  analysis_date = StringField()

  gender_check = StringField(choices=['unconfirmed', 'confirm', 'deviation'],
                             default='unconfirmed')
  phenotype_terms = ListField(EmbeddedDocumentField(PhenotypeTerm))
  # madeline info is a full xml file

### CLASS VARIABLES ###

    date_regex = re.compile('^(\d{4})-(\d{2})-(\d{2})$')
    date_no_dashes_regex = re.compile('^(\d{4})(\d{2})(\d{2})$')
    year_regex = re.compile('^\d\d\d\d$')

    ### MONGOENGINE FIELDS ###

    discogs_id = mongoengine.IntField(primary_key=True)
    artists = mongoengine.EmbeddedDocumentListField('ArtistCredit')
    companies = mongoengine.EmbeddedDocumentListField('CompanyCredit')
    country = mongoengine.StringField()
    #data_quality = mongoengine.StringField()
    extra_artists = mongoengine.EmbeddedDocumentListField('ArtistCredit')
    formats = mongoengine.EmbeddedDocumentListField('Format')
    genres = mongoengine.ListField(mongoengine.StringField())
    identifiers = mongoengine.EmbeddedDocumentListField('Identifier')
    labels = mongoengine.EmbeddedDocumentListField('LabelCredit')
    master_id = mongoengine.IntField()
    release_date = mongoengine.DateTimeField()
    #status = mongoengine.StringField()
    styles = mongoengine.ListField(mongoengine.StringField())
    title = mongoengine.StringField()
    tracklist = mongoengine.EmbeddedDocumentListField('Track')

    ### MONGOENGINE META ###

    meta = {
        'indexes': [
            '#title',
            '$title',
            'discogs_id',

# the pkglist, because mongoengine does not allow to modify existing items in the list
        # and add new items to the list at the same time.
        self.save()
        self.pkglist += collections_to_add
        self.save()


class PackageGroup(UnitMixin, ContentUnit):
    # TODO add docstring to this class
    package_group_id = mongoengine.StringField(required=True)
    repo_id = mongoengine.StringField(required=True)

    description = mongoengine.StringField()
    default_package_names = mongoengine.ListField()
    optional_package_names = mongoengine.ListField()
    mandatory_package_names = mongoengine.ListField()
    name = mongoengine.StringField()
    default = mongoengine.BooleanField(default=False)
    display_order = mongoengine.IntField()
    user_visible = mongoengine.BooleanField(default=False)
    translated_name = mongoengine.DictField()
    translated_description = mongoengine.DictField()
    langonly = mongoengine.StringField()
    conditional_package_names = mongoengine.ListField()

    # For backward compatibility
    _ns = mongoengine.StringField(default='units_package_group')
    _content_type_id = mongoengine.StringField(required=True, default='package_group')

    unit_key_fields = ('package_group_id', 'repo_id')
    unit_display_name = 'Package Group'
    unit_description = 'Yum Package group information'

class Questions(Document):
    questionId = StringField(unique=True)
    questionType = IntField(default = 0)
    questionDescription = StringField()# special formatted inside the description itself
    pictures = ListField(StringField())
    options = StringField()
    answer = StringField()
    hint = StringField()
    explanation = StringField()
    time = IntField()
    xp = IntField()
    tagsAllSubjects = ListField(StringField()) #categorynameIndex , ....
    tagsAllIndex = ListField(StringField())
    tags=ListField(StringField())
    meta = {
        'indexes': [
                    'tags',
                    'tagsAllSubjects',
                    'tagsAllIndex'
                ]
        }
    
    
    
    
    @staticmethod
    def addQuestion(questionId, questionType ,questionDescription , pictures, options, answer, hint , explanation , time, xp , tags):
        questionId = str(questionId)
        question = Questions.objects(questionId=questionId)