Source code for nidaqmx.system._collections.persisted_channel_collection

from import Sequence

from nidaqmx.errors import DaqError
from nidaqmx.error_codes import DAQmxErrors
from import PersistedChannel, _PersistedChannelAlternateConstructor
from nidaqmx.utils import unflatten_channel_string

[docs]class PersistedChannelCollection(Sequence): """ Contains the collection of global channels for a DAQmx system. This class defines methods that implements a container object. """ def __init__(self, interpreter): """ Do not construct this object directly; instead, call nidaqmx.system.System.local().global_channels. """ self._interpreter = interpreter def __contains__(self, item): channel_names = self.global_channel_names if isinstance(item, str): items = unflatten_channel_string(item) return all([i in channel_names for i in items]) elif isinstance(item, PersistedChannel): return item._name in channel_names def __eq__(self, other): if isinstance(other, self.__class__): return True return False def __getitem__(self, index): """ Indexes a subset of global channels on this global channel collection. Args: index: The value of the index. The following index types are supported: - str: Name of the global channel. 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 global channel in the collection. - slice: Range of the indexes/positions of global channels in the collection. Returns: List[]: Indicates the of global channels indexed. """ if isinstance(index, int): return _PersistedChannelAlternateConstructor(self.global_channel_names[index], self._interpreter) elif isinstance(index, slice): return [_PersistedChannelAlternateConstructor(name, self._interpreter) for name in self.global_channel_names[index]] elif isinstance(index, str): names = unflatten_channel_string(index) if len(names) == 1: return _PersistedChannelAlternateConstructor(names[0], self._interpreter) return [_PersistedChannelAlternateConstructor(name, self._interpreter) for name in names] else: raise DaqError( 'Invalid index type "{}" used to access collection.' .format(type(index)), DAQmxErrors.UNKNOWN) def __iter__(self): for channel_name in self.global_channel_names: yield _PersistedChannelAlternateConstructor(channel_name, self._interpreter) def __len__(self): return len(self.global_channel_names) def __ne__(self, other): return not self.__eq__(other) def __reversed__(self): channel_names = self.global_channel_names channel_names.reverse() for channel_name in channel_names: yield _PersistedChannelAlternateConstructor(channel_name, self._interpreter) @property def global_channel_names(self): """ List[str]: The names of all the global channels on this collection. """ val = self._interpreter.get_system_info_attribute_string(0x1265) return unflatten_channel_string(val)