Implement condition __str__

Author: rajveerappan

boto3/dynamodb/conditions.py

@@ -20,6 +20,7 @@
 )
 
 ATTR_NAME_REGEX = re.compile(r'[^.\[\]]+(?![^\[]*\])')
+EXPR_STR_FORMAT_REGEX = re.compile(r"\{(\d+)\}")
 
 
 class ConditionBase:
@@ -60,6 +61,14 @@ def __eq__(self, other):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def __str__(self) -> str:
+        format_str = EXPR_STR_FORMAT_REGEX.sub(
+            r"{values[\1]}", self.expression_format
+        )
+        return format_str.format(
+            values=self._values, operator=self.expression_operator
+        )
+
 
 class AttributeBase:
     def __init__(self, name):
@@ -133,6 +142,9 @@ def __eq__(self, other):
     def __ne__(self, other):
         return not self.__eq__(other)
 
+    def __str__(self) -> str:
+        return self.name
+
 
 class ConditionAttributeBase(ConditionBase, AttributeBase):
     """This base class is for conditions that can have attribute methods.