Django rest framework: name 'Serializer' not defined - django

Question

I have two models which have one to many relationship and I want to serialize the related fields on both ends.
The models:
class Mechanic(models.Model):
name = models.CharField('Name', max_length=256)
status = models.CharField('Status', choices=constants.MECHANIC_STATUS, default=constants.MECHANIC_STATUS[0][0],
max_length=64)
current_lat = models.CharField('Current Latitude', max_length=64)
current_lng = models.CharField('Current Longitude', max_length=64)
def __str__(self):
return self.name
class Service(models.Model):
type = models.CharField('Service Type', choices=constants.SERVICE_TYPES,
default=constants.SERVICE_TYPES[0][0], max_length=64)
mechanic = models.ForeignKey(Mechanic, on_delete=models.CASCADE, related_name='services')
vehicle_type = models.CharField('Vehicle Type', choices=constants.VEHICLE_TYPES,
default=constants.VEHICLE_TYPES[0][0], max_length=64)
charges = models.IntegerField('Charges')
def __str__(self):
return "{}, {}".format(self.mechanic, self.type)
The serializers:
class ServiceSerializer(serializers.ModelSerializer):
mechanic = MechanicSerializer(read_only=True) # Throws an error
class Meta:
model = Service
fields = ('id', 'type', 'mechanic', 'vehicle_type', 'charges')
class MechanicSerializer(serializers.ModelSerializer):
services = ServiceSerializer(many=True, read_only=True)
class Meta:
model = Mechanic
fields = ('id', 'name', 'status', 'services', 'current_lat', 'current_lng')
read_only_fields = ('id',)
How do I approach this problem? I understand that I've created a cyclic dependency because both serializers depend on each other.
Is there a better way to do it?

Answer 1

as an extenstion to my comment in the OP, create a new serializer class of Mechanic model before the ServiceSerializer class
class MechanicShortSerializer(serializers.ModelSerializer):
class Meta:
model = Mechanic
fields = '__all__'
class ServiceSerializer(serializers.ModelSerializer):
mechanic = MechanicShortSerializer(read_only=True) # replace with new serializer
class Meta:
model = Service
fields = ('id', 'type', 'mechanic', 'vehicle_type', 'charges')
class MechanicSerializer(serializers.ModelSerializer):
services = ServiceSerializer(many=True, read_only=True)
class Meta:
model = Mechanic
fields = ('id', 'name', 'status', 'services', 'current_lat', 'current_lng')
read_only_fields = ('id',)