compat for Abs

Author: isuruf

symengine/functions.py

@@ -2,4 +2,4 @@
     asin, acos, atan, acot, acsc, asec,
     sinh, cosh, tanh, coth, sech, csch,
     asinh, acosh, atanh, acoth, asech, acsch,
-    gamma, log, atan2, sqrt, exp)
+    gamma, log, atan2, sqrt, exp, Abs)

symengine/lib/symengine_wrapper.pyx

@@ -1476,6 +1476,10 @@ mul = Mul
 
 class Abs(OneArgFunction):
 
+    def __new__(cls, x):
+        cdef Basic X = _sympify(x)
+        return c2py(symengine.abs(X.thisptr))
+
     def _sympy_(Basic self):
         cdef RCP[const symengine.Abs] X = symengine.rcp_static_cast_Abs(self.thisptr)
         arg = c2py(deref(X).get_arg())._sympy_()

symengine/tests/test_sympy_compat.py

@@ -1,6 +1,6 @@
 from symengine.sympy_compat import (Integer, Rational, S, Basic, Add, Mul,
     Pow, symbols, Symbol, log, sin, cos, sech, csch, zeros, atan2, Number, Float,
-    Min, Max, RealDouble, have_mpfr)
+    Min, Max, RealDouble, have_mpfr, Abs)
 from symengine.utilities import raises
 
 
@@ -185,3 +185,7 @@ def __init__(self, name, extra_attribute):
     two_x = 2 * x
     # Check that after arithmetic, same subclass is returned
     assert two_x.args[1] is x
+
+def test_Abs():
+    x = symbols("x")
+    assert Abs(x) == Abs(-x)