jello 0.3.1

Filter JSON and JSON Lines data with Python syntax.

jello

Filter JSON and JSON Lines data with Python syntax

jello is similar to jq in that it processes JSON and JSON Lines data except jello uses standard python dict and list syntax.

JSON or JSON Lines can be piped into jello (JSON Lines are automatically slurped into a list of dictionaries) and are available as the variable _. Assign the output the the variable r to print as JSON or simple lines.

Install

pip3 install --upgrade jello

Usage

<JSON Data> | jello [OPTIONS] query

query can be most any valid python code as long as the result is assigned to r. _ is the sanitized JSON from STDIN presented as a python dict or list of dicts. For example:

$ cat data.json | jello 'r = _["key"]'

A convenience function called lines() outputs each element on its own line for output suitable to be assigned to a bash array:

$ cat data.json | jello 'r = lines(_["key"])'

Options

• -c compact print JSON output instead of pretty printing
• -r raw output of selected keys (no quotes)
• -n print selected null values
• -h help
• -v version info

Examples:

lambda functions and math

$ echo '{"t1":-30, "t2":-20, "t3":-10, "t4":0}' | jello '\
keys = _.keys()
vals = _.values()
cel = list(map(lambda x: (float(5)/9)*(x-32), vals))
r = dict(zip(keys, cel))'

{
  "t1": -34.44444444444444,
  "t2": -28.88888888888889,
  "t3": -23.333333333333336,
  "t4": -17.77777777777778
}

$ jc -a | jello 'r = len([entry for entry in _["parsers"] if "darwin" in entry["compatible"]])'

32

for loops

Output as JSON array

jc -a | jello '\
r = []
for entry in _["parsers"]:
  if "darwin" in entry["compatible"]:
    r.append(entry["name"])'

[
  "airport",
  "airport_s",
  "arp",
  "crontab",
  "crontab_u",
  ...
]

Output as bash array

jc -a | jello -r '\
r = []
for entry in _["parsers"]:
  if "darwin" in entry["compatible"]:
    r.append(entry["name"])
r = lines(r)'

airport
airport_s
arp
crontab
crontab_u
...

List and Dictionary Comprehension

Output as JSON arrauy

$ jc -a | jello 'r = [entry["name"] for entry in _["parsers"] if "darwin" in entry["compatible"]]'

[
  "airport",
  "airport_s",
  "arp",
  "crontab",
  "crontab_u",
  ...
]

Output as bash array

$ jc -a | jello -r 'r = lines([entry["name"] for entry in _["parsers"] if "darwin" in entry["compatible"]])'

airport
airport_s
arp
crontab
crontab_u
...

Environment Variables

$ echo '{"login_name": "joeuser"}' | jello '\
r = True if os.getenv("LOGNAME") == _["login_name"] else False'

true