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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 dummy(DF, cols=None):
 	"""Dummy code select columns of a DataFrame."""

	dummies = (get_dummies(DF[col]) for col in 
		(DF.columns if cols is None else cols))
	return concat(dummies, axis=1, keys=DF.columns)