Use Python’s standard-library csv module to read and write tabular text records whose fields are separated by commas, tabs, colons, or other delimiters. section 6.18
A practical workflow is to:
- Open the input and output files, preferably with with, and process the input one line at a time. section 6.30
- Configure the delimiter to match the data: commas for ordinary CSV, tabs for TSV-style output, or colons for passwd-style records. section 6.18
- Use csv readers and writers rather than manually splitting and joining fields. section 6.18
Converting passwd records
A passwd_to_csv function reads colon-separated records, skips comment lines or records without a user ID, and writes each username with its user ID separated by tabs. The input may contain comments and fields beyond the selected indexes. section 6.18
import csv
with open('/tmp/stuff.csv', 'w') as f:
o = csv.writer(f) #1
o.writerow(range(5)) #2
o.writerow(['a', 'b', 'c', 'd', 'e']) #3
A compact writer example shows creating a csv.writer and emitting rows from Python values. section 6.18
