[Documentation] Use exeutorlib with pandas Dataframes

[jan-janssen]

Add an example how to use executorlib with Pandas Dataframes:

import pandas
from executorlib import SingleNodeExecutor

def compute(a, b):
    return (a-b) / (a+b)

df = pandas.DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]})
df["c"] = df[["a", "b"]].apply(lambda x: compute(x.a, x.b), axis=1)

The same can be done with Executorlib using:

with SingleNodeExecutor() as exe:
    df["c"] = list(exe.map(compute, df["a"], df["b"]))