Make mypy happy

Author: rocky

mathics/core/atoms.py

@@ -132,7 +132,7 @@ def to_mpmath(self, precision: Optional[int] = None) -> mpmath.ctx_mp_python.mpf
                 return mpmath.mpf(self.value)
         return mpmath.mpf(self.value)
 
-    def to_python(self, *_, **kwargs):
+    def to_python(self, *_, **kwargs) -> Union[int, float, complex]:
         """Returns a native builtin Python object
         something in (int, float, complex, str, tuple, list or dict.).
         (See discussions in
@@ -838,7 +838,7 @@ def to_python(self, *args, **kwargs) -> Union[int, float, complex]:
         Returns a Python equivalent value for this complex number.
         """
         if self.imag.sameQ(Integer0):
-            return self.real
+            return self.real.to_python(*args, **kwargs)
 
         return complex(
             self.real.to_python(*args, **kwargs), self.imag.to_python(*args, **kwargs)