datatable.Frame.nunique1()

Count the number of unique values for a one-column frame and return it as a scalar.

This function is a shortcut for:

DT.nunique()[0, 0]

Parameters

return
int
except
ValueError

If called on a Frame that has more or less than one column.

See Also

  • .nunique() – similar to this method, but can be applied to a Frame with an arbitrary number of columns.