13 Feb
2019
13 Feb
'19
5:50 p.m.
Dear list,
I have the following to Pandas Series: a, b. I want to slice and then subtract. Like this: a[1:4] - b[0:3]. Why does it give me NaN? But it works in Numpy.
Example 1: did not work
a = pd.Series([85, 86, 87, 86]) b = pd.Series([15, 72, 2, 3]) a[1:4]-b[0:3] 0 NaN 1 14.0 2 85.0 3 NaN type(a[1:4])
<class 'pandas.core.series.Series'>
Example 2: worked If I use values() method, it's converted to a Numpy object. And it works!
a.values[1:4]-b.values[0:3]
array([71, 15, 84])
type(a.values[1:4])
<class 'numpy.ndarray'>
What's the reason that Pandas in example 1 did not work? Isn't Numpy built on top of Pandas? So, why is everything ok in Numpy, but not in Pandas?
Thanks in advance!