CSV (comma-separated values) is a text format for exchanging tabulated data: rows contain records, and commas separate fields. It suits sales data, exam results, research data, and application storage. section 11.2
Process CSV data in Python with the standard-library csv module:
- Use csv.reader to iterate over rows, receiving each row as a list of string values. section 11.2.1
- Open files with newline="" for cross-platform newline handling. section 11.2.1
- Use csv.DictReader when the first row names the fields; it yields dictionaries keyed by those headers. section 11.2.2
- Convert the reader to list when the application needs all rows available at once. section 11.2.1
Reading task records
For a tasks.txt file containing task_id,title,urgency followed by task rows, csv.DictReader produces dictionaries such as {'task_id': '1001', 'title': 'Homework', 'urgency': '5'}. The values remain strings in this treatment. section 11.2.2
Listing 11.9 Reading a CSV file using the csv module
import csv #1
with open("tasks.txt", newline="") as file:
csv_reader = csv.reader(file)
for row in csv_reader:
print(row)
# output the following lines: #2
['1001', 'Homework', '5']
['1002', 'Laundry', '3']
['1003', 'Grocery', '4']
Inspect the complete reader pattern and its printed row output. section 11.2.1
