def test_has_value(self):
class A(object):
def __init__(self):
self.n = 10
self.assertEqual(h.has_value(A(), "n"), (True, 10))
self.assertEqual(h.has_value(A(), "d"), (False, None))
self.assertEqual(h.has_value(dict(n=10), "n"), (True, 10))
self.assertEqual(h.has_value(dict(v=10), "n"), (False, None))
self.assertEqual(h.has_value(None, "n"), (False, None))
def get_value(self, source):
"""Apply self.convert to the source. The parameter passed to convert depends on
self.source_name. If source_name is given, self.convert(getattr(source, source_name)) is called,
otherwise self.convert(source) is called.
"""
if self.source_name is None:
present, value = True, self.convert(source)
converted = True
else:
present, value = has_value(source, self.source_name)
converted = False
if not present or value is None:
if self.is_required:
raise ValueError("required value not present")
else:
return None
else:
if converted:
return value
else:
return self.convert(value)