Python script to extract columns from a CSV file
Here's how I would do it, without Pandas:
import csv

filename = 'Book2.csv'

with open(filename, 'r') as csvfile:
    reader = csv.reader(csvfile)
    fields = next(reader) # Reads header row as a list
    rows = list(reader)   # Reads all subsequent rows as a list of lists

for column_number, field in enumerate(fields): # (0, routers), (1, servers)
    print(field)
    for row in rows:
        print(row[column_number])
    print('\n')