blob: 5dee0a744b2a99e1e88c52dfecfec56a8598d10f [file] [log] [blame]
Olivier Deprezf4ef2d02021-04-20 13:36:24 +02001r"""Command-line tool to validate and pretty-print JSON
2
3Usage::
4
5 $ echo '{"json":"obj"}' | python -m json.tool
6 {
7 "json": "obj"
8 }
9 $ echo '{ 1.2:3.4}' | python -m json.tool
10 Expecting property name enclosed in double quotes: line 1 column 3 (char 2)
11
12"""
13import argparse
14import json
15import sys
16
17
18def main():
19 prog = 'python -m json.tool'
20 description = ('A simple command line interface for json module '
21 'to validate and pretty-print JSON objects.')
22 parser = argparse.ArgumentParser(prog=prog, description=description)
23 parser.add_argument('infile', nargs='?',
24 type=argparse.FileType(encoding="utf-8"),
25 help='a JSON file to be validated or pretty-printed',
26 default=sys.stdin)
27 parser.add_argument('outfile', nargs='?',
28 type=argparse.FileType('w', encoding="utf-8"),
29 help='write the output of infile to outfile',
30 default=sys.stdout)
31 parser.add_argument('--sort-keys', action='store_true', default=False,
32 help='sort the output of dictionaries alphabetically by key')
33 parser.add_argument('--no-ensure-ascii', dest='ensure_ascii', action='store_false',
34 help='disable escaping of non-ASCII characters')
35 parser.add_argument('--json-lines', action='store_true', default=False,
36 help='parse input using the JSON Lines format. '
37 'Use with --no-indent or --compact to produce valid JSON Lines output.')
38 group = parser.add_mutually_exclusive_group()
39 group.add_argument('--indent', default=4, type=int,
40 help='separate items with newlines and use this number '
41 'of spaces for indentation')
42 group.add_argument('--tab', action='store_const', dest='indent',
43 const='\t', help='separate items with newlines and use '
44 'tabs for indentation')
45 group.add_argument('--no-indent', action='store_const', dest='indent',
46 const=None,
47 help='separate items with spaces rather than newlines')
48 group.add_argument('--compact', action='store_true',
49 help='suppress all whitespace separation (most compact)')
50 options = parser.parse_args()
51
52 dump_args = {
53 'sort_keys': options.sort_keys,
54 'indent': options.indent,
55 'ensure_ascii': options.ensure_ascii,
56 }
57 if options.compact:
58 dump_args['indent'] = None
59 dump_args['separators'] = ',', ':'
60
61 with options.infile as infile, options.outfile as outfile:
62 try:
63 if options.json_lines:
64 objs = (json.loads(line) for line in infile)
65 else:
66 objs = (json.load(infile), )
67 for obj in objs:
68 json.dump(obj, outfile, **dump_args)
69 outfile.write('\n')
70 except ValueError as e:
71 raise SystemExit(e)
72
73
74if __name__ == '__main__':
75 try:
76 main()
77 except BrokenPipeError as exc:
78 sys.exit(exc.errno)