Question

I’m trying to use pytest on Jython. And I’m getting stuck right at the beginning.

I’ve successfully installed the pytest package with easy_install:

$ ./jython easy_install pytest

When I try to run example from this page, things go wrong. I receive an extremely long failure report, like the one bellow. Does anybody have any idea why this is happening?

py.test-jython

============================= test session starts ==============================
platform java1.6.0_37 — Python 2.5.3 — pytest-2.3.2
collected 1 items

test_sample.py F

=================================== FAILURES ===================================
_________________ test_answer __________________

def test_answer():

  assert func(3) == 5

test_sample.py:5:

---

self = AssertionError()

def __init__(self, *args):
    BuiltinAssertionError.__init__(self, *args)
    if args:
        try:
            self.msg = str(args[0])
        except py.builtin._sysex:
            raise
        except:
            self.msg = "<[broken __repr__] %s at %0xd>" %(
                args[0].__class__, id(args[0]))
    else:
        f = py.code.Frame(sys._getframe(1))
        try:
            source = f.code.fullsource
            if source is not None:
                try:
                    source = source.getstatement(f.lineno, assertion=True)
                except IndexError:
                    source = None
                else:
                    source = str(source.deindent()).strip()
        except py.error.ENOENT:
            source = None
            # this can also occur during reinterpretation, when the
            # co_filename is set to "<run>".
        if source:

          self.msg = reinterpret(source, f, should_fail=True)

../jython2.5.3/Lib/site-packages/pytest-2.3.2-py2.5.egg/_pytest/assertion/reinterpret.py:32:

---

source = ‘assert func(3) == 5’, frame =
should_fail = True

def interpret(source, frame, should_fail=False):
    mod = ast.parse(source)
    visitor = DebugInterpreter(frame)
    try:

      visitor.visit(mod)

../jython2.5.3/Lib/site-packages/pytest-2.3.2-py2.5.egg/_pytest/assertion/newinterpret.py:49:

---

.
.
.

---

self = <_pytest.assertion.newinterpret.DebugInterpreter object at 0x4>
name = Name

def visit_Name(self, name):

  explanation, result = self.generic_visit(name)

../jython2.5.3/Lib/site-packages/pytest-2.3.2-py2.5.egg/_pytest/assertion/newinterpret.py:147:

---

self = <_pytest.assertion.newinterpret.DebugInterpreter object at 0x4>
node = Name

def generic_visit(self, node):
    # Fallback when we don't have a special implementation.
    if _is_ast_expr(node):
        mod = ast.Expression(node)
        co = self._compile(mod)
        try:
            result = self.frame.eval(co)
        except Exception:
            raise Failure()
        explanation = self.frame.repr(result)
        return explanation, result
    elif _is_ast_stmt(node):
        mod = ast.Module([node])
        co = self._compile(mod, "exec")
        try:
            self.frame.exec_(co)
        except Exception:
            raise Failure()
        return None, None
    else:

      raise AssertionError("can't handle %s" %(node,))

E AssertionError: can’t handle Name

../jython2.5.3/Lib/site-packages/pytest-2.3.2-py2.5.egg/_pytest/assertion/newinterpret.py:134: AssertionError
=========================== 1 failed in 0.55 seconds ===========================

Answer 1

Pytest has a workaround for jython’s lacking AST implementation, see issue1479. I just extended the workaround on the pytest side to work on jython-2.5.3. You can install a dev-candidate of pytest with:

pip install -i http://pypi.testrun.org -U pytest

and should get at least version 2.3.4.dev1 with “py.test-jython –version” and get assertions working with jython-2.5.3.