python · jeffreyrack · Aug 7, 2017 · Aug 7, 2017 · Sep 30, 2017 · Sep 30, 2017
diff --git a/Lib/json/tool.py b/Lib/json/tool.py
@@ -15,6 +15,25 @@
 import json
 import sys

+def parse_json_from_filehandle(infile, sort_keys):
+    try:
+        if sort_keys:
+            return json.load(infile)
+        else:
+            return json.load(infile,
+                            object_pairs_hook=collections.OrderedDict)
+    except ValueError as e:
+        raise SystemExit(e)
+
+def parse_json_from_string(input, sort_keys):
+    try:
+        if sort_keys:
+            return json.loads(input)
+        else:
+            return json.loads(input,
+                            object_pairs_hook=collections.OrderedDict)
+    except ValueError as e:
+        raise SystemExit(e)

 def main():
    prog = 'python -m json.tool'
@@ -27,23 +46,28 @@ def main():
                        help='write the output of infile to outfile')
    parser.add_argument('--sort-keys', action='store_true', default=False,
                        help='sort the output of dictionaries alphabetically by key')
+    parser.add_argument('--jsonlines', action='store_true', default=False,
+                        help='parse input using the jsonlines format')
    options = parser.parse_args()

    infile = options.infile or sys.stdin
    outfile = options.outfile or sys.stdout
    sort_keys = options.sort_keys
-    with infile:
-        try:
-            if sort_keys:
-                obj = json.load(infile)
-            else:
-                obj = json.load(infile,
-                                object_pairs_hook=collections.OrderedDict)
-        except ValueError as e:
-            raise SystemExit(e)
+    jsonlines = options.jsonlines
+    objs = []
+
+    if jsonlines:
+        with infile:
+            for line in infile:
+                objs.append(parse_json_from_string(line, sort_keys))
+    else:
+        with infile:
+            objs = [parse_json_from_filehandle(infile, sort_keys)]
+
    with outfile:
-        json.dump(obj, outfile, sort_keys=sort_keys, indent=4)
-        outfile.write('\n')
+        for obj in objs:
+            json.dump(obj, outfile, sort_keys=sort_keys, indent=4)
+            outfile.write('\n')


 if __name__ == '__main__':

diff --git a/Lib/test/test_json/test_tool.py b/Lib/test/test_json/test_tool.py
@@ -60,6 +60,27 @@ class TestTool(unittest.TestCase):
    ]
    """)

+    jsonlines_data = """\
+    {"ingredients":["frog", "water", "chocolate", "glucose"]}
+    {"ingredients":["chocolate","steel bolts"]}\
+    """
+
+    jsonlines_expect = textwrap.dedent("""\
+    {
+        "ingredients": [
+            "frog",
+            "water",
+            "chocolate",
+            "glucose"
+        ]
+    }
+    {
+        "ingredients": [
+            "chocolate",
+            "steel bolts"
+        ]
+    }""")
+
    def test_stdin_stdout(self):
        args = sys.executable, '-m', 'json.tool'
        with Popen(args, stdin=PIPE, stdout=PIPE, stderr=PIPE) as proc:
@@ -92,6 +113,13 @@ def test_infile_outfile(self):
        self.assertEqual(out, b'')
        self.assertEqual(err, b'')

+    def test_jsonlines(self):
+        args = sys.executable, '-m', 'json.tool', '--jsonlines'
+        with Popen(args, stdin=PIPE, stdout=PIPE, stderr=PIPE) as proc:
+            out, err = proc.communicate(self.jsonlines_data.encode())
+        self.assertEqual(out.splitlines(), self.jsonlines_expect.encode().splitlines())
+        self.assertEqual(err, b'')
+
    def test_help_flag(self):
        rc, out, err = assert_python_ok('-m', 'json.tool', '-h')
        self.assertEqual(rc, 0)

diff --git a/Misc/NEWS.d/next/Library/2017-10-01-09-15-12.bpo-31553.0EubUh.rst b/Misc/NEWS.d/next/Library/2017-10-01-09-15-12.bpo-31553.0EubUh.rst
@@ -0,0 +1,2 @@
+Add the --jsonlines option to json.tool in order to be able to parse input
+sent using the jsonlines format.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Add the --jsonlines option to json.tool in order to be able to parse input
		sent using the jsonlines format.