Python/One-Liners

Here's the trick to using python as a one liner: sys.stdin.read()

quick example

echo "zero one two three" | python -c 'import sys; print(sys.stdin.read().split(" ")[2])

Above, we print sample output and pipe it to a python program..

The Python takes everything from stdin and reads it into a string, turns it into a list by splitting at spaces, and prints the third item in the list.

parsing json

To parse json, use -m json.tool:

$ curl "https://git.charlesreid1.com/api/v1/user/repos?access_token=a936efc887b1947561ab901d08abe3b3b3128a80" | python -m json.tool

exit codes

To illustrate the difference in how bash treats exit codes: 0 means process completed normally/successfully, 1 means error:

(Note: In bash, && means "only run this code if the prior command succeeds.")

$ python && echo "hello world"
>>> import sys
>>> sys.exit(0)
hello world
$ 

$ python && echo "hello world"
>>> import sys
>>> sys.exit(1)
$