>>> from pandas import Series, DataFrame
>>> s = Series([0.1, 1.2, 2.3, 3.4, 4.5], index = ['a', 'b', 'c', 'd', 'e'])
>>> s['a']
0.1
>>> s[0]
0.1
>>> s[['a', 'c']]
a    0.1
c    2.3
dtype: float64
>>> s[[0, 2]]
a    0.1
c    2.3
dtype: float64
>>> s[s > 2]
c    2.3
d    3.4
e    4.5
dtype: float64

>>> s1 = Series({'a': 0.1, 'b': 1.2, 'c': 2.3})
>>> s2 = Series({'a': 1.0, 'b': 2.0, 'c': 3.0})
>>> s1 + s2
a    1.1
b    3.2
c    5.3
dtype: float64