Pandas Series index: Setting labels instead of RangeIndex

By default, a Python Pandas series has a RangeIndex, like a string or list:

s = pd.Series([10, 20, 30])
s.index  # RangeIndex(start=0, stop=3, step=1)

Set an index like this:

s = pd.Series([10, 20, 30], index=list('abc'))
s.index  # Index(['a', 'b', 'c'], dtype='str')