Miscellaneous improvements

^^^^^^^^^^^^^^^^^^^^^^^^^^

* improved the error message when selecting several labels at the same time and some of them were wrong.

In that case, it was hard to know which labels were wrong. This was especially annoying if the axis was long and

thus not shown in its entirety in the error message. For example, given the following array: ::

>>> arr = la.ndtest('a=a0,a1;b=b0..b2,b4..b7')

>>> arr

a\b b0 b1 b2 b4 b5 b6 b7

a0 0 1 2 3 4 5 6

a1 7 8 9 10 11 12 13

This code: ::

>>> arr['b0,b2,b3,b7']

used to produce the following error: ::

ValueError: 'b0,b2,b3,b7' is not a valid label for any axis:

a [2]: 'a0' 'a1'

b [7]: 'b0' 'b1' 'b2' ... 'b5' 'b6' 'b7'

which did not contain enough information to determine the problem was with 'b3'. It now produces this instead: ::

ValueError: 'b0,b2,b3,b7' is not a valid subset for any axis:

a [2]: 'a0' 'a1'

b [7]: 'b0' 'b1' 'b2' ... 'b5' 'b6' 'b7'

Some of those labels are valid though:

* axis 'b' contains 3 out of 4 labels (missing labels: 'b3')

Closes :issue:`1101`.

# if the key has several labels

nicer_key = _to_key(axis_key)

sequence_types = (tuple, list, np.ndarray, ABCArray)

if (isinstance(nicer_key, sequence_types) or

(isinstance(nicer_key, Group) and isinstance(nicer_key.key, sequence_types))):

# we use a different "base" message in this case (because axis_key is not really a *label*)

msg = f"{axis_key!r} is not a valid subset for any axis:\n{self._axes_summary()}"

# ... and check for partial matches

if isinstance(nicer_key, Group):

nicer_key = nicer_key.eval()

key_label_set = set(nicer_key)

partial_matches = {}

for axis in self:

missing_labels = key_label_set - set(axis.labels)

if missing_labels < key_label_set:

partial_matches[axis] = missing_labels

if partial_matches:

partial_matches_str = '\n'.join(

f" * axis '{self.axis_id(axis)}' contains {len(key_label_set) - len(missing_labels)}"

f' out of {len(key_label_set)}'

f' labels (missing labels: {", ".join(repr(label) for label in missing_labels)})'

for axis, missing_labels in partial_matches.items()

)

msg += f"\nSome of those labels are valid though:\n{partial_matches_str}"

else:

# we have single label

msg = f"{axis_key!r} is not a valid label for any axis:\n{self._axes_summary()}"

raise ValueError(msg)

with must_raise(ValueError, """[998, 999] is not a valid subset for any axis:

with must_raise(ValueError, """[999, 4] is not a valid subset for any axis:

* axis 'a' contains 1 out of 2 labels (missing labels: 999)"""):