def test_minus2(self):
     val = sympify('x-2*y')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_expr))
     self.assertEqual(py.to_string(), '-2 * y + x')
 def test_inv(self):
     val = sympify('(a/b)**i')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_expr))
     self.assertEqual(py.to_string(), '(a / b)**i')
 def test_plus(self):
     val = sympify('x+y')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_expr))
     self.assertEqual(py.to_string(), 'y + x')
 def test_rational(self):
     val = sympify('3/4')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_expr))
     self.assertEqual(py.to_string(), '3 / 4.0')
 def test_one(self):
     val = sympify('a**2')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_expr))
     self.assertEqual(py.to_string(), 'a**2')
 def test_pi(self):
   val = sympify('pi')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_var))
   self.assertEqual(py.to_string(),'math.pi')
 def test_pi(self):
     val = sympify('pi')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_var))
     self.assertEqual(py.to_string(), 'math.pi')
 def test_minus3(self):
   val = sympify('z-2*y*z')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_expr))
   self.assertEqual(py.to_string(),'z + -2 * y * z')
 def test_minus4(self):
   val = sympify('2*exp(-r)-3*x*exp(-r)')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_expr))
   self.assertEqual(py.to_string(),'-3 * x * math.exp(-r) + 2 * math.exp(-r)')
 def test_plus(self):
   val = sympify('x+y')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_expr))
   self.assertEqual(py.to_string(),'y + x')
 def test_minus2(self):
   val = sympify('x-2*y')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_expr))
   self.assertEqual(py.to_string(),'-2 * y + x')
 def test_inv(self):
   val = sympify('(a/b)**i')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_expr))
   self.assertEqual(py.to_string(),'(a / b)**i')
 def test_one(self):
   val = sympify('a**2')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_expr))
   self.assertEqual(py.to_string(),'a**2')
 def test_rational(self):
   val = sympify('3/4')
   py = expr_to_py(val)
   self.assert_(isinstance(py,py_expr))
   self.assertEqual(py.to_string(),'3 / 4.0')
 def test_minus3(self):
     val = sympify('z-2*y*z')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_expr))
     self.assertEqual(py.to_string(), 'z + -2 * y * z')
 def test_one(self):
     val = sympify('a+b')
     py = expr_to_py(val)
     self.assertEqual(py.to_string(), 'b + a')
 def test_minus4(self):
     val = sympify('2*exp(-r)-3*x*exp(-r)')
     py = expr_to_py(val)
     self.assert_(isinstance(py, py_expr))
     self.assertEqual(py.to_string(),
                      '-3 * x * math.exp(-r) + 2 * math.exp(-r)')
 def test_one(self):
   val = sympify('a+b')
   py = expr_to_py(val)
   self.assertEqual(py.to_string(),'b + a')