COMPAT: implement visit_Constant for 3.8 compat

Closes pandas-dev#27261

Author: TomAugspurger

doc/source/whatsnew/v1.0.0.rst

@@ -205,6 +205,7 @@ ExtensionArray
 Other
 ^^^^^
 - Trying to set the ``display.precision``, ``display.max_rows`` or ``display.max_columns`` using :meth:`set_option` to anything but a ``None`` or a positive int will raise a ``ValueError`` (:issue:`23348`)
+- Compatibility with Python 3.8 in :meth:`DataFrame.query` (:issue:`27261`)
 
 
 .. _whatsnew_1000.contributors:

pandas/core/computation/expr.py

@@ -582,6 +582,9 @@ def visit_NameConstant(self, node, **kwargs):
     def visit_Num(self, node, **kwargs):
         return self.const_type(node.n, self.env)
 
+    def visit_Constant(self, node, **kwargs):
+        return self.const_type(node.n, self.env)
+
     def visit_Str(self, node, **kwargs):
         name = self.env.add_tmp(node.s)
         return self.term_type(name, self.env)