from datetime import date

weekNumber = date.today().isocalendar()[1]

currentweek = "week"+str(weekNumber)

from django.db import models
from Taskmanager.email_info import currentweek

class Taskmanager(models.Model):
    CurrentSprint = models.CharField(max_length=10,
                                     default=currentweek,
                                     choices=week_number)
    todaydate = models.DateField()

class Tasksadd(forms.ModelForm):
    todaydate = forms.DateField(widget=forms.SelectDateWidget,
                                initial=datetime.date.today())
    class Meta:
        model = Taskmanager
        fields = [
                  'CurrentSprint', 'todaydate',
                 ]

<div class="container">
    <div class="row ml-auto">
        <div class="col-sm-offset-3 col-sm-6">
                 <form method="POST" action=".">
                  {% csrf_token %}
                   </br>
                    <h3>Add tasks here:</h3>
                      {{ form|crispy }}
                         <input type="submit" name="submit"
                             class="btn btn-info"
                             placeholder="Submit">
                  </form>
               </div>
        </div>
 </div>

from datetime import date

def currentweek():
    weekNumber = date.today().isocalendar()[1]
    return  = "week{}".format(weekNumber)