csv.writer
Create an object that writes rows in CSV format.
Python 3.13
csv.writer(csvfile, dialect='excel', **fmtparams)Parameters
- csvfileTextIO
- A file open for writing with newline='', or io.StringIO.
- dialectstr | Dialectoptional
- A set of format settings; 'excel' by default, which is comma-separated CSV.
- **fmtparamsAny
- Individual settings, such as delimiter=';' or lineterminator for the line ending.
Return value
A writer object with the writerow(row) and writerows(rows) methods.
Examples
Writing a table to a file
Python 3.13
import csv
with open('people.csv', 'w', newline='', encoding='utf-8') as file:
writer = csv.writer(file)
writer.writerow(['name', 'age'])
writer.writerows([['Anna', 25], ['Boris', 31]])
with open('people.csv', encoding='utf-8') as file:
print(file.read(), end='')name,age Anna,25 Boris,31
Quotes are added automatically
Python 3.13
import csv
import io
buffer = io.StringIO()
writer = csv.writer(buffer, lineterminator='\n')
writer.writerow(['Moscow', 'big, busy', 'say "hi"'])
print(buffer.getvalue(), end='')Moscow,"big, busy","say ""hi"""
Details
Values containing the separator, quotes or a line break are quoted automatically, and quotes inside are doubled. Each row ends with \r\n, so open the file with newline='', otherwise empty lines appear between rows on Windows. Numbers and other values are written with str, and None as an empty string.