Traceback (most recent call last):


 "C:\Users\thaar\PycharmProjects\sklearn-dev\birch_test.py", line 61, in <module>

clusterer.fit(X)


 "C:\Program 
s\Python37\lib\site-packages\sklearn\cluster\_birch.py", line 463, in fit

return self._fit(X)


 "C:\Program 
s\Python37\lib\site-packages\sklearn\cluster\_birch.py", line 510, in _fit

self.root_.append_subcluster(new_subcluster1)


 "C:\Program 
s\Python37\lib\site-packages\sklearn\cluster\_birch.py", line 158, in append_subcluster

self.init_sq_norm_[n_samples] = subcluster.sq_norm_
AttributeError: '_CFSubcluster' object has no attribute 'sq_norm_'

Traceback (most recent call last):


 "n.py", line 23, in <module>

Foo()


 "n.py", line 15, in __init__

self.mypy_does_not_typecheck_this()
# no error
AttributeError: 'Foo' object has no attribute 'mypy_does_not_typecheck_this'
