#16333: use (",", ": ") as default separator when indent is specified to avoid trailing whitespace. Patch by Serhiy Storchaka.
diff --git a/Doc/library/json.rst b/Doc/library/json.rst
index f9547cb..25a3358 100644
--- a/Doc/library/json.rst
+++ b/Doc/library/json.rst
@@ -155,9 +155,13 @@
.. versionchanged:: 3.2
Allow strings for *indent* in addition to integers.
- If *separators* is an ``(item_separator, dict_separator)`` tuple, then it
- will be used instead of the default ``(', ', ': ')`` separators. ``(',',
- ':')`` is the most compact JSON representation.
+ If specified, *separators* should be an ``(item_separator, key_separator)``
+ tuple. The default is ``(', ', ': ')`` if *indent* is ``None`` and
+ ``(',', ': ')`` otherwise. To get the most compact JSON representation,
+ you should specify ``(',', ':')`` to eliminate whitespace.
+
+ .. versionchanged:: 3.4
+ Use ``(',', ': ')`` as default if *indent* is not ``None``.
*default(obj)* is a function that should return a serializable version of
*obj* or raise :exc:`TypeError`. The default simply raises :exc:`TypeError`.
@@ -394,8 +398,12 @@
Allow strings for *indent* in addition to integers.
If specified, *separators* should be an ``(item_separator, key_separator)``
- tuple. The default is ``(', ', ': ')``. To get the most compact JSON
- representation, you should specify ``(',', ':')`` to eliminate whitespace.
+ tuple. The default is ``(', ', ': ')`` if *indent* is ``None`` and
+ ``(',', ': ')`` otherwise. To get the most compact JSON representation,
+ you should specify ``(',', ':')`` to eliminate whitespace.
+
+ .. versionchanged:: 3.4
+ Use ``(',', ': ')`` as default if *indent* is not ``None``.
If specified, *default* is a function that gets called for objects that can't
otherwise be serialized. It should return a JSON encodable version of the
diff --git a/Lib/json/__init__.py b/Lib/json/__init__.py
index 86a7a3e..7314cb4 100644
--- a/Lib/json/__init__.py
+++ b/Lib/json/__init__.py
@@ -148,9 +148,10 @@
level of 0 will only insert newlines. ``None`` is the most compact
representation.
- If ``separators`` is an ``(item_separator, dict_separator)`` tuple
- then it will be used instead of the default ``(', ', ': ')`` separators.
- ``(',', ':')`` is the most compact JSON representation.
+ If specified, ``separators`` should be an ``(item_separator, key_separator)``
+ tuple. The default is ``(', ', ': ')`` if *indent* is ``None`` and
+ ``(',', ': ')`` otherwise. To get the most compact JSON representation,
+ you should specify ``(',', ':')`` to eliminate whitespace.
``default(obj)`` is a function that should return a serializable version
of obj or raise TypeError. The default simply raises TypeError.
@@ -209,9 +210,10 @@
level of 0 will only insert newlines. ``None`` is the most compact
representation.
- If ``separators`` is an ``(item_separator, dict_separator)`` tuple
- then it will be used instead of the default ``(', ', ': ')`` separators.
- ``(',', ':')`` is the most compact JSON representation.
+ If specified, ``separators`` should be an ``(item_separator, key_separator)``
+ tuple. The default is ``(', ', ': ')`` if *indent* is ``None`` and
+ ``(',', ': ')`` otherwise. To get the most compact JSON representation,
+ you should specify ``(',', ':')`` to eliminate whitespace.
``default(obj)`` is a function that should return a serializable version
of obj or raise TypeError. The default simply raises TypeError.
diff --git a/Lib/json/encoder.py b/Lib/json/encoder.py
index ba57c2c..93b5ea7 100644
--- a/Lib/json/encoder.py
+++ b/Lib/json/encoder.py
@@ -127,9 +127,10 @@
indent level. An indent level of 0 will only insert newlines.
None is the most compact representation.
- If specified, separators should be a (item_separator, key_separator)
- tuple. The default is (', ', ': '). To get the most compact JSON
- representation you should specify (',', ':') to eliminate whitespace.
+ If specified, separators should be an (item_separator, key_separator)
+ tuple. The default is (', ', ': ') if *indent* is ``None`` and
+ (',', ': ') otherwise. To get the most compact JSON representation,
+ you should specify (',', ':') to eliminate whitespace.
If specified, default is a function that gets called for objects
that can't otherwise be serialized. It should return a JSON encodable
@@ -145,6 +146,8 @@
self.indent = indent
if separators is not None:
self.item_separator, self.key_separator = separators
+ elif indent is not None:
+ self.item_separator = ','
if default is not None:
self.default = default
diff --git a/Lib/test/json_tests/test_indent.py b/Lib/test/json_tests/test_indent.py
index 4c70646..4eb4f89 100644
--- a/Lib/test/json_tests/test_indent.py
+++ b/Lib/test/json_tests/test_indent.py
@@ -32,6 +32,8 @@
d1 = self.dumps(h)
d2 = self.dumps(h, indent=2, sort_keys=True, separators=(',', ': '))
d3 = self.dumps(h, indent='\t', sort_keys=True, separators=(',', ': '))
+ d4 = self.dumps(h, indent=2, sort_keys=True)
+ d5 = self.dumps(h, indent='\t', sort_keys=True)
h1 = self.loads(d1)
h2 = self.loads(d2)
@@ -42,6 +44,8 @@
self.assertEqual(h3, h)
self.assertEqual(d2, expect.expandtabs(2))
self.assertEqual(d3, expect)
+ self.assertEqual(d4, d2)
+ self.assertEqual(d5, d3)
def test_indent0(self):
h = {3: 1}