Person - Skills many-to-many and Skill level - django-models

Question

I'm trying to relate Persons, their Skills and Skill levels. My model looks like this:
class Person(models.Model):
first_name = models.CharField(max_length=200)
middle_name = models.CharField(max_length=200, blank=True)
last_name = models.CharField(max_length=200)
skills = models.ManyToManyField(Skill)
and
class Skill(models.Model):
name = models.CharField(max_length=200)
description = models.CharField(max_length=1000, blank=True)
active = models.BooleanField(default=True)
It does work (in admin) and I'm able to create a Person, add several skills etc. However, I also need the skill level information for each Skill related to each Person. Something like this:
BASIC = 'BAS'
NOVICE = 'NOV'
INTERMEDIATE = 'INT'
ADVANCED = 'ADV'
EXPERT = 'EXP'
SKILL_LEVEL_CHOICES = (
(BASIC, 'Basic knowledge'),
(NOVICE, 'Novice (Limited experience)'),
(INTERMEDIATE, 'Intermediate (Practical application)'),
(ADVANCED, 'Advanced knowledge'),
(EXPERT, 'Expert'),
)
I'm not sure what should I add to Person to have information for each skill and its level.
Thanks.

Answer 1

After gathering a little bit more experience on Django, I realized that it offers pretty simple solution to my problem :)
I needed two classes, SkillLevel and SkillWithSkillLevel.
class SkillLevel(models.Model):
name = models.CharField(max_length=20)
description = models.CharField(max_length=100, blank=True)
class SkillWithSkillLevel(models.Model):
skill = models.ForeignKey(Skill)
level = models.ForeignKey(SkillLevel)
person = models.ForeignKey(Person)
That's it.
It helps to have a little bit customized admin:
class SkillWithSkillLevelInline(admin.TabularInline):
model = SkillWithSkillLevel
extra = 3
And then, of course, register SkillWithSkillLevelInline within PersonAdmin, inlines = [SkillWithSkillLevelInline]
Person obviously doesn't need skills = models.ManyToManyField(Skill).