Export singleton sets from S

Co-authored-by: Isuru Fernando <[email protected]>

Author: rikardn

symengine/__init__.py

@@ -1,3 +1,5 @@
+import symengine.lib.symengine_wrapper as wrapper
+
 from .lib.symengine_wrapper import (
     have_mpfr, have_mpc, have_flint, have_piranha, have_llvm, have_llvm_long_double,
     I, E, pi, oo, zoo, nan, Symbol, Dummy, S, sympify, SympifyError,
@@ -12,7 +14,7 @@
     LessThan, StrictGreaterThan, StrictLessThan, Eq, Ne, Ge, Le,
     Gt, Lt, And, Or, Not, Nand, Nor, Xor, Xnor, perfect_power, integer_nthroot,
     isprime, sqrt_mod, Expr, cse, count_ops, ccode, Piecewise, Contains, Interval, FiniteSet,
-    EmptySet, UniversalSet, Reals, Integers, linsolve,
+    linsolve,
     FunctionSymbol as AppliedUndef,
     golden_ratio as GoldenRatio,
     catalan as Catalan,
@@ -22,6 +24,13 @@
 from .functions import *
 from .printing import init_printing
 
+
+EmptySet = wrapper.S.EmptySet
+UniversalSet = wrapper.S.UniversalSet
+Reals = wrapper.S.Reals
+Integers = wrapper.S.Integers
+
+
 if have_mpfr:
     from .lib.symengine_wrapper import RealMPFR
 
@@ -38,6 +47,12 @@ def lambdify(args, exprs, **kwargs):
 __version__ = "0.6.1"
 
 
+# To not expose internals
+del lib.symengine_wrapper
+del lib
+del wrapper
+
+
 def test():
     import pytest
     import os

symengine/tests/test_solve.py

@@ -7,10 +7,10 @@ def test_solve():
     x = Symbol("x")
     reals = Interval(-oo, oo)
 
-    assert solve(1, x, reals) == EmptySet()
+    assert solve(1, x, reals) == EmptySet
     assert solve(0, x, reals) == reals
     assert solve(x + 3, x, reals) == FiniteSet(-3)
-    assert solve(x + 3, x, Interval(0, oo)) == EmptySet()
+    assert solve(x + 3, x, Interval(0, oo)) == EmptySet
     assert solve(x, x, reals) == FiniteSet(0)
     assert solve(x**2 + 1, x) == FiniteSet(-I, I)
     assert solve(x**2 - 2*x + 1, x) == FiniteSet(1)