'Pick some channels.
Parameters
ch_names : list
The list of channels to select.
Returns
inst : instance of Raw, Epochs, or Evoked
The modified instance.
See Also
drop_channels
Notes
.. versionadded:: 0.9.0'

def pick_channels(self, ch_names):

    _check_excludes_includes(ch_names)
    idx = [self.ch_names.index(c) for c in ch_names if (c in self.ch_names)]
    self._pick_drop_channels(idx)
    return self
