1 r"""Command-line tool to validate and pretty-print JSON 2 3 Usage:: 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 """ 13 import argparse 14 import collections 15 import json 16 import sys 17 18 19 def main(): 20 prog = 'python -m json.tool' 21 description = ('A simple command line interface for json module ' 22 'to validate and pretty-print JSON objects.') 23 parser = argparse.ArgumentParser(prog=prog, description=description) 24 parser.add_argument('infile', nargs='?', type=argparse.FileType(), 25 help='a JSON file to be validated or pretty-printed') 26 parser.add_argument('outfile', nargs='?', type=argparse.FileType('w'), 27 help='write the output of infile to outfile') 28 parser.add_argument('--sort-keys', action='store_true', default=False, 29 help='sort the output of dictionaries alphabetically by key') 30 options = parser.parse_args() 31 32 infile = options.infile or sys.stdin 33 outfile = options.outfile or sys.stdout 34 sort_keys = options.sort_keys 35 with infile: 36 try: 37 if sort_keys: 38 obj = json.load(infile) 39 else: 40 obj = json.load(infile, 41 object_pairs_hook=collections.OrderedDict) 42 except ValueError as e: 43 raise SystemExit(e) 44 with outfile: 45 json.dump(obj, outfile, sort_keys=sort_keys, indent=4) 46 outfile.write('\n') 47 48 49 if __name__ == '__main__': 50 main() 51
