def __getitem__(self, index):
"""
Indexes a subset of custom scales on this collection.
Args:
index: The value of the index. The following index types
are supported:
- str: Name of the custom scale. You also can specify
a string that contains a list or range of names to
this input. If you have a list of names, use the
DAQmx Flatten Channel String function to convert
the list to a string.
- int: Index/position of the custom scale in the
collection.
- slice: Range of the indexes/positions of custom scales
in the collection.
Returns:
List[nidaqmx.system.storage.persisted_scale.PersistedScale]:
Indicates the subset of custom scales indexed.
"""
if isinstance(index, six.integer_types):
return PersistedScale(self.scale_names[index])
elif isinstance(index, slice):
return [PersistedScale(name) for name in self.scale_names[index]]
elif isinstance(index, six.string_types):
names = unflatten_channel_string(index)
if len(names) == 1:
return PersistedScale(names[0])
return [PersistedScale(name) for name in names]
else:
raise DaqError(
'Invalid index type "{0}" used to access collection.'.format(
type(index)), DAQmxErrors.UNKNOWN.value)
def make(cls, scale_type) -> Dict[str, Union[int, str]]:
assert Scale.From.supports(
scale_type), f'value {scale_type} not supported for scaling.'
if cls._should_make():
if not hasattr(cls, 'made_scales'):
cls.made_scales = set()
if not cls.name() in cls.made_scales:
try:
PersistedScale(cls.name()).delete()
except nidaqmx.DaqError:
pass
cls._make()
cls.made_scales.add(cls.name())
return dict(units=scale_type, custom_scale_name=cls.name())
return {}
def __reversed__(self):
scale_names = self.scale_names
scale_names.reverse()
for scale_name in scale_names:
yield PersistedScale(scale_name)
def __iter__(self):
for scale_name in self.scale_names:
yield PersistedScale(scale_name)