Rational: Add p, q attributes from sympy.

Author: mattwala

symengine/lib/symengine_wrapper.pyx

@@ -956,6 +956,14 @@ cdef class Rational(Number):
     def is_Rational(self):
         return True
 
+    @property
+    def p(self):
+        return self.get_num_den()[0]
+
+    @property
+    def q(self):
+        return self.get_num_den()[1]
+
     def get_num_den(self):
         cdef RCP[const symengine.Integer] _num, _den
         symengine.get_num_den(deref(symengine.rcp_static_cast_Rational(self.thisptr)),

symengine/tests/test_sympy_compat.py

@@ -11,6 +11,8 @@ def test_Rational():
     i = S(1)/2
     assert isinstance(i, Rational)
     assert isinstance(i, Basic)
+    assert i.p == 1
+    assert i.q == 2
 
 def test_Add():
     x, y = symbols("x y")