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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_sngl_snrs(self, instruments=None):
 		""" 		Get the single-detector SNRs for each row in the table. 		"""

		if len(self) and instruments is None:
			instruments = map(str, \
			                instrument_set_from_ifos(self[0].ifos))
		elif instruments is None:
			instruments = []
		return dict((ifo, self.get_sngl_snr(ifo))\
		            for ifo in instruments)