use Pool to parallelize directory reading

[alexlib]

1. read carefully and optimize genfromtxt https://numpy.org/doc/stable/user/basics.io.genfromtxt.html
2. read how to read ascii files in parallel from the disk using Pool https://waterprogramming.wordpress.com/2015/08/26/basic-parallelization-in-python/

[alexlib]

also try astropy reader

https://docs.astropy.org/en/stable/io/ascii/index.html

or pandas read_csv

import glob
import pandas as pd

# glob.glob('data*.csv') - returns List[str]
# pd.read_csv(f) - returns pd.DataFrame()
# for f in glob.glob() - returns a List[DataFrames]
# pd.concat() - returns one pd.DataFrame()
df = pd.concat([pd.read_csv(f) for f in glob.glob('data*.csv')], ignore_index = True)