修复判断验证码是否存在的时候，用户不存在导致的报错

account/serializers.py

@@ -7,7 +7,7 @@ from .models import User
 class UserLoginSerializer(serializers.Serializer):
     username = serializers.CharField(max_length=30)
     password = serializers.CharField(max_length=30)
-    captcha = serializers.CharField(required=False,min_length=4,max_length=4)
+    captcha = serializers.CharField(required=False, min_length=4, max_length=4)
 
 
 class UsernameCheckSerializer(serializers.Serializer):

account/views.py

@@ -26,17 +26,15 @@ class UserLoginAPIView(APIView):
         serializer = UserLoginSerializer(data=request.data)
         if serializer.is_valid():
             data = serializer.data
-            user = User.objects.get(username=data["username"])
-            # 只有管理员才适用验证码登录
-            if user.admin_type > 0:
-                if not "captcha" in data:
-                    return error_response(u"请填写验证码！")
-                captcha = Captcha(request)
-                if not captcha.check(data["captcha"]):
-                    return error_response(u"验证码错误")
             user = auth.authenticate(username=data["username"], password=data["password"])
             # 用户名或密码错误的话 返回None
             if user:
+                if user.admin_type > 0:
+                    if "captcha" not in data:
+                        return error_response(u"请填写验证码！")
+                    captcha = Captcha(request)
+                    if not captcha.check(data["captcha"]):
+                        return error_response(u"验证码错误")
                 auth.login(request, user)
                 return success_response(u"登录成功")
             else: