How to read CSV w/ the Python csv module: csv.reader() & csv.DictReader()

There are two ways to read data from CSV files using Python’s built-in module ‘csv’.

1. csv.Reader()
2. csv.DictReader()

Let’s explore the difference between the two options using an example .csv file: friends_birthdays.csv – it looks something like this:

csv.Reader()

csv.Reader() let’s you read & access data in .csv files using indexes, and it great for simple .csv files.

Using csv.Reader() to explore the friends_birthdays.csv file:

import csv

with open('friends_birthdays.csv') as f:
    my_csv = csv.reader(f, delimiter=',')
    line_count = 0
    for row in my_csv:
        print(f'{row[0]} lives in {row[1]} and has a birthday in {row[2]}.')

### output
# name lives in location and has a birthday in birthday_month
# Anthony lives in Tokyo and has a birthday in June
# Alex lives in Maryland and has a birthday in September

Notice how this prints the header row in the output.

To remove that you can adjust your code to remove the header row by first turning your read csv into a list, and then slicing off the top row.

import csv

with open('friends_birthdays.csv') as f:
    my_csv = list(csv.reader(f))
    my_csv = my_csv[1:]
    for row in my_csv:
        print(f'{row[0]} lives in {row[1]} and birthday is {row[2]}')

### output
# Anthony lives in Tokyo and birthday is June
# Alex lives in Maryland and birthday is September

csv.DictReader()

csv.DictReader() is a more convenient option when working with larger CSV files, but can still work for simper .csv files as well.

Using csv.DictReader() to explore the friends_birthdays.csv file:

import csv

with open('friends_birthdays.csv') as file:
    my_csv = csv.DictReader(file, delimiter=',')
    line_count = 0
    for row in my_csv:
        print(f"{row['name']} lives in {row['location']} and has a birthday in {row['birthday_month']}.")

### output
# Anthony lives in Tokyo and has a birthday in June.
# Alex lives in Maryland and has a birthday in September.