CSV

Reading CSV files

• csv.reader() : input is CSV file.

csv_file.txt

Sabrina Green,802-867-5309,System Administrator
Eli Jones,684-3481127,IT specialist
Melody Daniels,846-687-7436,Programmer
Charlie Rivera,698-746-3357,Web Developer

import csv
 f = open("csv_file.txt")
 csv_f = csv.reader(f)
 for row in csv_f:
     name, phone, role = row
     print("Name: {}, Phone: {}, Role: {}".format(name, phone, role))
f.close()

Output:

Name: Sabrina Green, Phone: 802-867-5309, Role: System Administrator
Name: Eli Jones, Phone: 684-3481127, Role: IT specialist
Name: Melody Daniels, Phone: 846-687-7436, Role: Programmer
Name: Charlie Rivera, Phone: 698-746-3357, Role: Web Developer

Generating CSV

• csv.writer() : input is a list with sublist, for example [[col1, col2, col3], [col1, col2, col3]] 
• .writerow() : 一次寫一筆
• .writerows() : 一次寫多筆

import csv

hosts = [["workstation.local", "192.168.25.46"],["webserver.cloud", "10.2.5.6"]]
with open('hosts.csv', 'w') as hosts_csv:
    writer = csv.writer(hosts_csv)
    writer.writerows(hosts)

Wit dictionary

Reading a CSV

• csv.DictReader() : input is a CSV file, 

# software.csv
# name,version,status,users
# MailTree,5.34,production,324
# CalDoor,1.25.1,beta,22
# Chatty Chicken,0.34,alpha,4

with open('software.csv') as software:
    reader = csv.DictReader(software)
    for row in reader:
        print(("{} has {} users").format(row["name"], row["users"]))

# Output:
# MailTree has 324 users
# CalDoor has 22 users
# Chatty Chicken has 4 users