6-read-and-write-csv-data.py

# 12.5 Read and Write CSV Data
# Solutions to Exercises


# Exercise 1
import csv
from pathlib import Path

numbers = [
    [1, 2, 3, 4, 5],
    [6, 7, 8, 9, 10],
    [11, 12, 13, 14, 15],
]

file_path = Path.home() / "numbers.csv"

with file_path.open(mode="w", encoding="utf-8") as file:
    writer = csv.writer(file)
    writer.writerows(numbers)


# Exercise 2
numbers = []

with file_path.open(mode="r", encoding="utf-8") as file:
    reader = csv.reader(file)
    for row in reader:
        int_row = [int(num) for num in row]
        numbers.append(int_row)

print(numbers)


# Exercise 3
favorite_colors = [
    {"name": "Joe", "favorite_color": "blue"},
    {"name": "Anne", "favorite_color": "green"},
    {"name": "Bailey", "favorite_color": "red"},
]

file_path = Path.home() / "favorite_colors.csv"

def change_key(color, old_key, new_key):
    value = color[old_key]
    del color[old_key]
    color[new_key] = value
    return color

favorite_colors =[change_key(color, 'favorite_color', 'favorite color')
                  for color in favorite_colors]

with file_path.open('w', encoding = 'utf-8') as file:
    writer = csv.DictWriter(file, favorite_colors[0].keys())
    writer.writeheader()
    writer.writerows(favorite_colors)

# Exercise 4
favorite_colors = []

with file_path.open('r', encoding = 'utf-8') as file:
    header = file.readline()
    header = header.replace('\n', '')
    header = header.split(',')
    
    reader = csv.DictReader(file, fieldnames = header)
    for row in reader:
        row = change_key(row, 'favorite color', 'favorite_color')
        favorite_colors.append(row)

print(favorite_colors)