tables.py

from django.utils.translation import ugettext_lazy as _
import django_tables2 as tables
from django_tables2.utils import A

class LessonsTable(tables.Table):
    class Meta:
        attrs = {'class': 'table table-striped table-bordered table-hover table-responsive-xl'}

    period__period = tables.Column(accessor='period.period')
    lesson__groups = tables.Column(accessor='lesson.group_names')
    lesson__teachers = tables.Column(accessor='lesson.teacher_names')
    lesson__subject = tables.Column(accessor='lesson.subject')
    room = tables.Column(accessor='room')

    def __init__(self, week, *args, **kwargs):
        self._week = week
        super().__init__(*args, **kwargs)