cpython/Lib/json/tool.py
Benjamin Peterson 940e207412 improve the command-line interface of json.tool (closes #21000)
A patch from Berker Peksag.
2014-03-21 23:17:29 -05:00

43 lines
1.2 KiB
Python

r"""Command-line tool to validate and pretty-print JSON
Usage::
$ echo '{"json":"obj"}' | python -m json.tool
{
"json": "obj"
}
$ echo '{ 1.2:3.4}' | python -m json.tool
Expecting property name enclosed in double quotes: line 1 column 3 (char 2)
"""
import argparse
import json
import sys
def main():
prog = 'python -m json.tool'
description = ('A simple command line interface for json module '
'to validate and pretty-print JSON objects.')
parser = argparse.ArgumentParser(prog=prog, description=description)
parser.add_argument('infile', nargs='?', type=argparse.FileType(),
help='a JSON file to be validated or pretty-printed')
parser.add_argument('outfile', nargs='?', type=argparse.FileType('w'),
help='write the output of infile to outfile')
options = parser.parse_args()
infile = options.infile or sys.stdin
outfile = options.outfile or sys.stdout
with infile:
try:
obj = json.load(infile)
except ValueError as e:
raise SystemExit(e)
with outfile:
json.dump(obj, outfile, sort_keys=True, indent=4)
outfile.write('\n')
if __name__ == '__main__':
main()