feat: FloatField optionally validates that the number is no less than or equals to a given value.

docs/api-guide/fields.md

@@ -280,7 +280,8 @@ Corresponds to `django.db.models.fields.FloatField`.
 
 - `max_value` Validate that the number provided is no greater than this value.
 - `min_value` Validate that the number provided is no less than this value.
-- `exclusive_min` If true, validate that the number provided is no greater than or equals `min_value`.
+- `exclusive_min` If true, validate that the number provided is no greater than or equals to `min_value`.
+- `exclusive_max` If true, validate that the number provided is no less than or equals to `max_value`.
 
 ## DecimalField
 

rest_framework/fields.py

@@ -38,7 +38,8 @@ from rest_framework.exceptions import ErrorDetail, ValidationError
 from rest_framework.settings import api_settings
 from rest_framework.utils import html, humanize_datetime, json, representation
 from rest_framework.utils.formatting import lazy_format
-from rest_framework.validators import ExclusiveLMinValueValidator, ProhibitSurrogateCharactersValidator
+from rest_framework.validators import (ExclusiveMaxValueValidator, ExclusiveMinValueValidator,
+                                       ProhibitSurrogateCharactersValidator)
 
 
 class empty:
@@ -967,6 +968,7 @@ class FloatField(Field):
     default_error_messages = {
         'invalid': _('A valid number is required.'),
         'max_value': _('Ensure this value is less than or equal to {max_value}.'),
+        'exclusive_max_value': _('Ensure this value is less than {max_value}.'),
         'min_value': _('Ensure this value is greater than or equal to {min_value}.'),
         'exclusive_min_value': _('Ensure this value is greater than {min_value}.'),
         'max_string_length': _('String value too large.')
@@ -977,8 +979,14 @@ class FloatField(Field):
         self.max_value = kwargs.pop('max_value', None)
         self.min_value = kwargs.pop('min_value', None)
         self.exclusive_min = kwargs.pop("exclusive_min", False)
+        self.exclusive_max = kwargs.pop("exclusive_max", False)
         super().__init__(**kwargs)
         if self.max_value is not None:
+            if self.exclusive_max:
+                message = lazy_format(self.error_messages["exclusive_max_value"], max_value=self.max_value)
+                self.validators.append(
+                    ExclusiveMaxValueValidator(self.max_value, message=message))
+            else:
                 message = lazy_format(self.error_messages['max_value'], max_value=self.max_value)
                 self.validators.append(
                     MaxValueValidator(self.max_value, message=message))
@@ -986,7 +994,7 @@ class FloatField(Field):
             if self.exclusive_min:
                 message = lazy_format(self.error_messages["exclusive_min_value"], min_value=self.min_value)
                 self.validators.append(
-                    ExclusiveLMinValueValidator(self.min_value, message=message))
+                    ExclusiveMinValueValidator(self.min_value, message=message))
             else:
                 message = lazy_format(self.error_messages['min_value'], min_value=self.min_value)
                 self.validators.append(

rest_framework/validators.py

@@ -281,9 +281,17 @@ class UniqueForYearValidator(BaseUniqueForValidator):
         return qs_filter(queryset, **filter_kwargs)
 
 
-class ExclusiveLMinValueValidator(BaseValidator):
+class ExclusiveMinValueValidator(BaseValidator):
     message = _('Ensure this value is greater than %(limit_value)s.')
     code = "exclusive_min_value"
 
     def compare(self, a, b):
         return a <= b
+
+
+class ExclusiveMaxValueValidator(BaseValidator):
+    message = _('Ensure this value is lesser than %(limit_value)s.')
+    code = "exclusive_max_value"
+
+    def compare(self, a, b):
+        return a >= b

tests/test_fields.py

@@ -1078,7 +1078,7 @@ class TestMinMaxFloatField(FieldValues):
 
 class TestExclusiveMinFloatField(FieldValues):
     """
-    Valid and invalid values for 'FloatField' with exclusive_min limits.
+    Valid and invalid values for 'FloatField' with exclusive_min limit.
     """
     valid_inputs = {
         '1.01': 1.01,
@@ -1096,6 +1096,27 @@ class TestExclusiveMinFloatField(FieldValues):
     field = serializers.FloatField(min_value=1, exclusive_min=True)
 
 
+class TestExclusiveMaxFloatField(FieldValues):
+    """
+    Valid and invalid values for 'FloatField' with exclusive_max limit.
+    """
+    valid_inputs = {
+        '1': 1,
+        '2.9': 2.9,
+        1: 1,
+        2.9: 2.9,
+        1.0: 1.0,
+    }
+
+    invalid_inputs = {
+        3: ['Ensure this value is less than 3.'],
+        '3': ['Ensure this value is less than 3.'],
+        '3.0': ['Ensure this value is less than 3.'],
+    }
+    outputs = {}
+    field = serializers.FloatField(max_value=3, exclusive_max=True)
+
+
 class TestDecimalField(FieldValues):
     """
     Valid and invalid values for `DecimalField`.