Improved pylint score of host module

apps/hosts/models.py

@@ -21,7 +21,7 @@ class ChallengeHostTeam(TimeStampedModel):
     team_url = models.CharField(max_length=1000, default="", blank=True)
 
     def __str__(self):
-        return "{0}: {1}".format(self.team_name, self.created_by)
+        return f"{self.team_name}: {self.created_by}"
 
     def get_all_challenge_host_email(self):
         email_ids = ChallengeHost.objects.filter(team_name=self).values_list(
@@ -72,9 +72,7 @@ class ChallengeHost(TimeStampedModel):
     permissions = models.CharField(max_length=30, choices=PERMISSION_OPTIONS)
 
     def __str__(self):
-        return "{0}:{1}:{2}".format(
-            self.team_name, self.user, self.permissions
-        )
+        return f"{self.team_name}:{self.user}:{self.permissions}"
 
     class Meta:
         app_label = "hosts"

apps/hosts/serializers.py

@@ -5,13 +5,14 @@
 
 
 class ChallengeHostTeamSerializer(serializers.ModelSerializer):
+    """Serializer for the ChallengeHostTeam model."""
 
     created_by = serializers.SlugRelatedField(
         slug_field="username", queryset=User.objects.all()
     )
 
     def __init__(self, *args, **kwargs):
-        super(ChallengeHostTeamSerializer, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         context = kwargs.get("context")
         if context:
             request = context.get("request")
@@ -23,6 +24,7 @@ class Meta:
 
 
 class ChallengeHostSerializer(serializers.ModelSerializer):
+    """Serializer for the ChallengeHost model."""
 
     status = serializers.ChoiceField(choices=ChallengeHost.STATUS_OPTIONS)
     permissions = serializers.ChoiceField(
@@ -33,7 +35,7 @@ class ChallengeHostSerializer(serializers.ModelSerializer):
     )
 
     def __init__(self, *args, **kwargs):
-        super(ChallengeHostSerializer, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         context = kwargs.get("context")
         if context:
             challenge_host_team = context.get("challenge_host_team")
@@ -47,26 +49,30 @@ class Meta:
 
 
 class InviteHostToTeamSerializer(serializers.Serializer):
+    """Serializer for inviting a host to join a team."""
 
     email = serializers.EmailField()
 
     def __init__(self, *args, **kwargs):
-        super(InviteHostToTeamSerializer, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
         context = kwargs.get("context")
         if context:
             self.challenge_host_team = context.get("challenge_host_team")
             self.user = context.get("request").user
 
     def validate_email(self, value):
+        """Validate the email to ensure it 
+        doesn't belong to the inviting user."""
         if value == self.user.email:
             raise serializers.ValidationError("A host cannot invite himself")
         try:
             User.objects.get(email=value)
-        except User.DoesNotExist:
-            raise serializers.ValidationError("User does not exist")
+        except User.DoesNotExist as exc:
+            raise serializers.ValidationError("User does not exist") from exc
         return value
 
-    def save(self):
+    def save(self, **kwargs):
+        """Create or get a ChallengeHost for the invited user."""
         email = self.validated_data.get("email")
         return ChallengeHost.objects.get_or_create(
             user=User.objects.get(email=email),
@@ -77,6 +83,7 @@ def save(self):
 
 
 class HostTeamDetailSerializer(serializers.ModelSerializer):
+    """Serializer for detailed information about host teams."""
 
     members = serializers.SerializerMethodField()
     created_by = serializers.SlugRelatedField(
@@ -87,7 +94,9 @@ class Meta:
         model = ChallengeHostTeam
         fields = ("id", "team_name", "created_by", "members", "team_url")
 
-    def get_members(self, obj):
+    @staticmethod
+    def get_members(obj):
+        """Get all members of a host team."""
         hosts = ChallengeHost.objects.filter(team_name_id=obj.id)
         serializer = ChallengeHostSerializer(hosts, many=True)
         return serializer.data

apps/hosts/urls.py

@@ -19,17 +19,21 @@
         name="create_challenge_host_team",
     ),
     url(
-        r"^challenge_host_team/(?P<challenge_host_team_pk>[0-9]+)/challenge_host$",
+        r"^challenge_host_team/"
+        r"(?P<challenge_host_team_pk>[0-9]+)/challenge_host$",
         views.challenge_host_list,
         name="get_challenge_host_list",
     ),
     url(
-        r"^challenge_host_team/(?P<challenge_host_team_pk>[0-9]+)/challenge_host/(?P<pk>[0-9]+)$",
+        r"^challenge_host_team/"
+        r"(?P<challenge_host_team_pk>[0-9]+)/"
+        r"challenge_host/(?P<pk>[0-9]+)$",
         views.challenge_host_detail,
         name="get_challenge_host_details",
     ),
     url(
-        r"^remove_self_from_challenge_host/(?P<challenge_host_team_pk>[0-9]+)$",
+        r"^remove_self_from_challenge_host/"
+        r"(?P<challenge_host_team_pk>[0-9]+)$",
         views.remove_self_from_challenge_host_team,
         name="remove_self_from_challenge_host_team",
     ),