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Category：Languages

I have a Pandas Series formed by list of terms:

`my_series = pd.Series([['a','b','c'], ['a','d'], [], ['e']]) `

Is there a better/more elegant/faster way of get a set of unique terms than doing like this?:

`lt = set() for l in my_series.tolist(): lt = lt.union(l) `

O(n) extended iterable unpacking with `set.union`

.

`>>> set().union(*my_series) {'a', 'b', 'c', 'd', 'e'} `

If you prefer old-fashioned, there's the set-comprehension equivalent -

`>>> {y for x in my_series for y in x} {'a', 'b', 'c', 'd', 'e'} `