pandas.Series.unique
Series.unique()[source]-
Return np.ndarray of unique values in the object. Significantly faster than numpy.unique. Includes NA values. The order of the original is preserved.
Returns: uniques : np.ndarray
© 2008–2012, AQR Capital Management, LLC, Lambda Foundry, Inc. and PyData Development Team
Licensed under the 3-clause BSD License.
https://pandas.pydata.org/pandas-docs/version/0.19.2/generated/pandas.Series.unique.html