Is this an attribute?

[Robert]

On Tuesday, January 19, 2016 at 3:52:12 PM UTC-5, Peter Otten wrote:
> Robert wrote:
> 
> > Hi,
> > 
> > When I read a code snippet below, I find I don't know what
> > 'self.framelogprob' is on the child class.
> > 
> > 
> > 
> > ////// parent class
> > class _BaseHMM(BaseEstimator):
> >     def __init__(self, n_components=1,
> >                  startprob_prior=1.0, transmat_prior=1.0,
> >                  algorithm="viterbi", random_state=None,
> >                  n_iter=10, tol=1e-2, verbose=False,
> >                  params=string.ascii_letters,
> >                  init_params=string.ascii_letters):
> >         self.n_components = n_components
> > ......
> > 
> >     def score_samples(self, X, lengths=None):
> >         X = check_array(X)
> >         n_samples = X.shape[0]
> >         logprob = 0
> >         posteriors = np.zeros((n_samples, self.n_components))
> >         for i, j in iter_from_X_lengths(X, lengths):
> >             framelogprob = self._compute_log_likelihood(X[i:j])
> > .......
> >         return logprob, posteriors
> > 
> > ////// child class
> > class StubHMM(_BaseHMM):
> >     def _compute_log_likelihood(self, X):
> >         return self.framelogprob
> > -------------
> > 
> > On Python web, it says that things after dot, such as a class name, are
> > attributes. From this definition, 'framelogprob' is an attribute. But when
> > I run the command on Canopy:
> > 
> > h.framelogprob
> > 
> ---------------------------------------------------------------------------
> > AttributeError                            Traceback (most recent call
> > last) <ipython-input-19-970ee2f3402c> in <module>()
> > ----> 1 h.framelogprob
> > 
> > AttributeError: 'StubHMM' object has no attribute 'framelogprob'
> > 
> > 
> > it doesn't recognize it as an attribute. What is wrong with my
> > understanding?
> 
> When you are reading a book, do you expect to be able to understand every 
> arbitrarily picked sentence without any idea about the surrounding text?
> 
> Widen your view a bit -- the StubHMM class is in a file test_base.py and 
> therefore it is likely that it is supposed to help with testing rather than 
> to be used standalone. When you read the complete module to understand more 
> of the context or just use a tool like grep you'll find the following 
> snippets:
> 
>         h = StubHMM(2)
>         h.transmat_ = [[0.7, 0.3], [0.3, 0.7]]
>         h.startprob_ = [0.5, 0.5]
>         h.framelogprob = self.framelogprob
> 
>         h = StubHMM(n_components)
>         h.framelogprob = self.framelogprob
> 
> So the attribute is set "from the outside". I wouldn't do that, I'd rather 
> add initializer arguments, but that wasn't the question...

I did not pay attention to the code you post. The attribute has been unclear
to me for sometime, especially for a child class. I just realize that class
attribute cannot be inherited to its child. 
Thanks