get_column_names.py $filename | grep -i coupon | \
python -c "import sys; print(','.join(line.strip() for line in sys.stdin))"

import fileinput
print("".join(sorted(fileinput.input(), key=len)))

On the command line:

% cat random_snippets.txt | python -c 'import fileinput; print("".join(sorted(fileinput.input(), key=len)))'

Ref:- https://stackoverflow.com/questions/34401683/how-to-use-awk-to-sort-lines-by-length/

See also:

• https://www.google.com/books/edition/The_Python_3_Standard_Library_by_Example/KtcnDwAAQBAJ?hl=en&gbpv=0 - The Python 3 Standard Library by Example - Doug Hellmann - 2017 . This book gives many sample scripts that make use of fileinput; The scripts are very practical in nature and explained well.

cat junk3.txt | \
python -c "import sys; print('\'', '\', \''.join(line.strip() for line in sys.stdin), '\'', sep='')"