protect sympy tests if no sympy

theano/scalar/basic_sympy.py

@@ -12,7 +12,6 @@ except ImportError:
     pass
 
 import itertools as it
-
 names = ("sympy_func_%d"%i for i in it.count(0))
 
 def include_line(line):

theano/scalar/tests/test_basic_sympy.py

 from theano.scalar.basic_sympy import SymPyCCode
 from theano.scalar.basic import floats
 import theano
-import sympy
 
-xs = sympy.Symbol('x')
-ys = sympy.Symbol('y')
+try:
+    import sympy
+    xs = sympy.Symbol('x')
+    ys = sympy.Symbol('y')
+except ImportError:
+    sympy = False
+
 xt, yt = floats('xy')
 
 def test_SymPyCCode():
+    if not sympy:       return
     op = SymPyCCode([xs, ys], xs + ys)
     e = op(xt, yt)
     g = theano.gof.FunctionGraph([xt, yt], [e])
@@ -15,12 +20,14 @@ def test_SymPyCCode():
     assert fn(1.0, 2.0) == 3.0
 
 def test_grad():
+    if not sympy:       return
     op = SymPyCCode([xs], xs**2)
     zt = op(xt)
     ztprime = theano.grad(zt, xt)
     assert ztprime.owner.op.expr == 2*xs
 
 def test_multivar_grad():
+    if not sympy:       return
     op = SymPyCCode([xs, ys], xs**2 + ys**2)
     zt = op(xt, yt)
     dzdx, dzdy = theano.grad(zt, [xt, yt])