Merge ~cjwatson/lazr.restful:remove-manual-pretty-printing into lazr.restful:main

[Colin Watson]

Remove most manual pretty-printing from webservice-marshallers.rst

This was only needed for Python 2/3 support.

We still need `pprint_dict`, because dicts only became order-preserving in Python 3.6.

[Guruprasad (lgp171188)]

I reviewed the diff and the changes look good to me. 👍

review: Approve

diff --git a/src/lazr/restful/docs/webservice-marshallers.rst b/src/lazr/restful/docs/webservice-marshallers.rst
index 0d18d2a..b32e0d2 100644
--- a/src/lazr/restful/docs/webservice-marshallers.rst
+++ b/src/lazr/restful/docs/webservice-marshallers.rst
@@ -21,33 +21,11 @@ application root.
 We also define some helpers to print values in a way that is unambiguous
 across Python versions.
 
-    >>> import six
-
-    >>> def pformat_value(value):
-    ...     """Pretty-format a single value."""
-    ...     if isinstance(value, six.text_type):
-    ...         value = value.encode('unicode_escape').decode('ASCII')
-    ...         if "'" in value and '"' not in value:
-    ...             return '"%s"' % value
-    ...         else:
-    ...             return "'%s'" % value.replace("'", "\\'")
-    ...     else:
-    ...         return repr(value)
-
-    >>> def pprint_value(value):
-    ...     """Pretty-print a single value."""
-    ...     print(pformat_value(value))
-
-    >>> def pprint_list(lst):
-    ...     print('[', end='')
-    ...     print(', '.join(pformat_value(value) for value in lst), end='')
-    ...     print(']')
-
     >>> def pprint_dict(d):
     ...     print('{', end='')
     ...     print(
     ...         ', '.join(
-    ...             '%s: %s' % (pformat_value(key), pformat_value(value))
+    ...             '%r: %r' % (key, value)
     ...             for key, value in sorted(d.items())),
     ...         end='')
     ...     print('}')
@@ -90,7 +68,7 @@ implementation, the value is returned unchanged.
     'foo'
     >>> marshaller.marshall_from_json_data(4)
     4
-    >>> print(marshaller.marshall_from_json_data(u"unicode\u2122"))
+    >>> print(marshaller.marshall_from_json_data("unicode\u2122"))
     unicode™
     >>> marshaller.marshall_from_json_data("")
     ''
@@ -114,16 +92,16 @@ string, the resulting value is passed on to marshall_from_json_data().
     >>> marshaller.marshall_from_request("false")
     False
     >>> marshaller.marshall_from_request('["True", "False"]')
-    [...'True', ...'False']
+    ['True', 'False']
     >>> marshaller.marshall_from_request("1")
     1
     >>> marshaller.marshall_from_request("-10.5")
     -10.5
-    >>> pprint_value(marshaller.marshall_from_request('"a string"'))
+    >>> marshaller.marshall_from_request('"a string"')
     'a string'
-    >>> pprint_value(marshaller.marshall_from_request('"false"'))
+    >>> marshaller.marshall_from_request('"false"')
     'false'
-    >>> pprint_value(marshaller.marshall_from_request('"null"'))
+    >>> marshaller.marshall_from_request('"null"')
     'null'
 
 Invalid JSON-encoded strings are interpreted as string literals and
@@ -131,7 +109,7 @@ passed on directly to marshall_from_json_data(). That's for the
 convenience of web clients, they don't need to encode string values in
 quotes, or can pass lists using multiple key-value pairs.
 
-    >>> pprint_value(marshaller.marshall_from_request(u"a string"))
+    >>> marshaller.marshall_from_request("a string")
     'a string'
     >>> marshaller.marshall_from_request('False')
     'False'
@@ -212,9 +190,9 @@ None is passed through though.
 Booleans are encoded using the standard JSON representation of 'true' or
 'false'.
 
-    >>> marshaller.marshall_from_request(u"true")
+    >>> marshaller.marshall_from_request("true")
     True
-    >>> marshaller.marshall_from_request(u"false")
+    >>> marshaller.marshall_from_request("false")
     False
 
     >>> marshaller.marshall_from_request('True')
@@ -250,7 +228,7 @@ Integers are encoded using strings when in a request.
 
     >>> marshaller.marshall_from_request("4")
     4
-    >>> marshaller.marshall_from_request(u"-4")
+    >>> marshaller.marshall_from_request("-4")
     -4
 
 It raises a ValueError if the value cannot be converted to an integer.
@@ -269,15 +247,15 @@ Note that python octal and hexadecimal syntax isn't supported.
 
 (This would 13 in octal notation.)
 
-    >>> marshaller.marshall_from_request(u"015")
+    >>> marshaller.marshall_from_request("015")
     Traceback (most recent call last):
       ...
-    ValueError: got '...', expected int: ...'015'
+    ValueError: got 'str', expected int: '015'
 
-    >>> marshaller.marshall_from_request(u"0x04")
+    >>> marshaller.marshall_from_request("0x04")
     Traceback (most recent call last):
       ...
-    ValueError: got '...', expected int: ...'0x04'
+    ValueError: got 'str', expected int: '0x04'
 
 Float
 -----
@@ -312,11 +290,11 @@ And integers are automatically converted to a float.
 
 Floats are encoded using the standard JSON representation.
 
-    >>> marshaller.marshall_from_request(u"1.2")
+    >>> marshaller.marshall_from_request("1.2")
     1.2
-    >>> marshaller.marshall_from_request(u"-1.2")
+    >>> marshaller.marshall_from_request("-1.2")
     -1.2
-    >>> marshaller.marshall_from_request(u"-1")
+    >>> marshaller.marshall_from_request("-1")
     -1.0
 
     >>> marshaller.marshall_from_request('True')
@@ -425,16 +403,16 @@ string. A ValueError is raised when that's not the case.
     >>> verifyObject(IFieldMarshaller, marshaller)
     True
 
-    >>> pprint_value(marshaller.marshall_from_json_data(u"Test"))
+    >>> marshaller.marshall_from_json_data("Test")
     'Test'
     >>> marshaller.marshall_from_json_data(1.0)
     Traceback (most recent call last):
       ...
-    ValueError: got 'float', expected ...: 1.0
+    ValueError: got 'float', expected str: 1.0
     >>> marshaller.marshall_from_json_data(b'Test')
     Traceback (most recent call last):
       ...
-    ValueError: got '...', expected ...: ...'Test'
+    ValueError: got 'bytes', expected str: b'Test'
 
 None is passed through though.
 
@@ -444,13 +422,13 @@ None is passed through though.
 When coming from the request, everything is interpreted as a unicode
 string:
 
-    >>> pprint_value(marshaller.marshall_from_request('a string'))
+    >>> marshaller.marshall_from_request('a string')
     'a string'
-    >>> pprint_value(marshaller.marshall_from_request(['a', 'b']))
+    >>> marshaller.marshall_from_request(['a', 'b'])
     "['a', 'b']"
-    >>> pprint_value(marshaller.marshall_from_request('true'))
+    >>> marshaller.marshall_from_request('true')
     'True'
-    >>> pprint_value(marshaller.marshall_from_request(''))
+    >>> marshaller.marshall_from_request('')
     ''
 
 Except that 'null' still returns None.
@@ -460,11 +438,11 @@ Except that 'null' still returns None.
 
 Line breaks coming from the request are normalized to LF.
 
-    >>> pprint_value(marshaller.marshall_from_request('abc\r\n\r\ndef\r\n'))
+    >>> marshaller.marshall_from_request('abc\r\n\r\ndef\r\n')
     'abc\n\ndef\n'
-    >>> pprint_value(marshaller.marshall_from_request('abc\n\ndef\n'))
+    >>> marshaller.marshall_from_request('abc\n\ndef\n')
     'abc\n\ndef\n'
-    >>> pprint_value(marshaller.marshall_from_request('abc\r\rdef\r'))
+    >>> marshaller.marshall_from_request('abc\r\rdef\r')
     'abc\n\ndef\n'
 
 Bytes
@@ -480,9 +458,9 @@ a string, a ValueError is raised.
     >>> verifyObject(IFieldMarshaller, marshaller)
     True
 
-    >>> pprint_value(marshaller.marshall_from_json_data(u"Test"))
+    >>> marshaller.marshall_from_json_data("Test")
     b'Test'
-    >>> pprint_value(marshaller.marshall_from_json_data(u'int\xe9ressant'))
+    >>> marshaller.marshall_from_json_data('int\xe9ressant')
     b'int\xc3\xa9ressant'
     >>> marshaller.marshall_from_json_data(1.0)
     Traceback (most recent call last):
@@ -497,21 +475,20 @@ Again, except for None which is passed through.
 When coming over the request, the value is also converted into a UTF-8
 encoded string, with no JSON decoding.
 
-    >>> pprint_value(marshaller.marshall_from_request(u"Test"))
+    >>> marshaller.marshall_from_request("Test")
     b'Test'
-    >>> pprint_value(marshaller.marshall_from_request(u'int\xe9ressant'))
+    >>> marshaller.marshall_from_request('int\xe9ressant')
     b'int\xc3\xa9ressant'
-    >>> pprint_value(marshaller.marshall_from_request(b'1.0'))
+    >>> marshaller.marshall_from_request(b'1.0')
     b'1.0'
-    >>> pprint_value(marshaller.marshall_from_request(b'"not JSON"'))
+    >>> marshaller.marshall_from_request(b'"not JSON"')
     b'"not JSON"'
 
 Since multipart/form-data can be used to upload data, file-like objects
 are read.
 
     >>> from io import BytesIO
-    >>> pprint_value(
-    ...     marshaller.marshall_from_request(BytesIO(b'A line of data')))
+    >>> marshaller.marshall_from_request(BytesIO(b'A line of data'))
     b'A line of data'
 
 Bytes field used in an entry are stored in the librarian, so their
@@ -547,12 +524,12 @@ ASCIILine is a subclass of Bytes but is marshalled like text.
 
 Unicode objects remain Unicode objects.
 
-    >>> pprint_value(marshaller.marshall_from_json_data(u"Test"))
+    >>> marshaller.marshall_from_json_data("Test")
     'Test'
 
 Note that the marshaller accepts character values where bit 7 is set.
 
-    >>> print(marshaller.marshall_from_json_data(u'int\xe9ressant'))
+    >>> print(marshaller.marshall_from_json_data('int\xe9ressant'))
     intéressant
 
 Non-string values like floats are rejected.
@@ -560,7 +537,7 @@ Non-string values like floats are rejected.
     >>> marshaller.marshall_from_json_data(1.0)
     Traceback (most recent call last):
       ...
-    ValueError: got 'float', expected ...: 1.0
+    ValueError: got 'float', expected str: 1.0
 
 None is passed through.
 
@@ -570,17 +547,17 @@ None is passed through.
 When coming from the request, everything is interpreted as a unicode
 string:
 
-    >>> pprint_value(marshaller.marshall_from_request('a string'))
+    >>> marshaller.marshall_from_request('a string')
     'a string'
-    >>> pprint_value(marshaller.marshall_from_request(['a', 'b']))
+    >>> marshaller.marshall_from_request(['a', 'b'])
     "['a', 'b']"
-    >>> pprint_value(marshaller.marshall_from_request('true'))
+    >>> marshaller.marshall_from_request('true')
     'True'
-    >>> pprint_value(marshaller.marshall_from_request(''))
+    >>> marshaller.marshall_from_request('')
     ''
-    >>> print(marshaller.marshall_from_request(u'int\xe9ressant'))
+    >>> print(marshaller.marshall_from_request('int\xe9ressant'))
     intéressant
-    >>> pprint_value(marshaller.marshall_from_request('1.0'))
+    >>> marshaller.marshall_from_request('1.0')
     '1.0'
 
 But again, 'null' is returned as None.
@@ -666,7 +643,7 @@ display them the way we want.
     ...     try:
     ...         callable(*args)
     ...     except ValueError as e:
-    ...         print('ValueError:', six.text_type(e))
+    ...         print('ValueError:', str(e))
 
 
 Choice of EnumeratedTypes
@@ -858,41 +835,41 @@ For sequences, the only JSON representation for the collection itself is a
 list, since that's the only sequence type available in JSON. Anything else
 will raise a ValueError.
 
-    >>> pprint_list(list_marshaller.marshall_from_json_data([u"Test"]))
+    >>> list_marshaller.marshall_from_json_data(["Test"])
     ['Test']
 
-    >>> list_marshaller.marshall_from_json_data(u"Test")
+    >>> list_marshaller.marshall_from_json_data("Test")
     Traceback (most recent call last):
       ...
-    ValueError: got '...', expected list: ...'Test'
+    ValueError: got 'str', expected list: 'Test'
 
 For dicts, we support marshalling from sequences of (name, value) pairs as
 well as from dicts or even strings which are interpreted as single element
 lists.
 
     >>> pprint_dict(
-    ...     dict_marshaller.marshall_from_json_data({u"foo": u"Vegetarian"}))
+    ...     dict_marshaller.marshall_from_json_data({"foo": "Vegetarian"}))
     {'foo': <Item Cuisine.VEGETARIAN, Vegetarian>}
 
     >>> pprint_dict(
-    ...     dict_marshaller.marshall_from_json_data([(u"foo", u"Vegetarian")]))
+    ...     dict_marshaller.marshall_from_json_data([("foo", "Vegetarian")]))
     {'foo': <Item Cuisine.VEGETARIAN, Vegetarian>}
 
-    >>> pprint_dict(dict_marshaller.marshall_from_request(u"foo,Vegetarian"))
+    >>> pprint_dict(dict_marshaller.marshall_from_request("foo,Vegetarian"))
     {'foo': <Item Cuisine.VEGETARIAN, Vegetarian>}
 
 If we attempt to marshall something other than one of the above data formats,
 a ValueError will be raised.
 
-    >>> dict_marshaller.marshall_from_json_data(u"Test")
+    >>> dict_marshaller.marshall_from_json_data("Test")
     Traceback (most recent call last):
       ...
-    ValueError: got '...', expected dict: ...'Test'
+    ValueError: got 'str', expected dict: 'Test'
 
-    >>> dict_marshaller.marshall_from_request(u"Test")
+    >>> dict_marshaller.marshall_from_request("Test")
     Traceback (most recent call last):
       ...
-    ValueError: got '[...'Test']', list of name,value pairs
+    ValueError: got '['Test']', list of name,value pairs
 
 None is passed through though.
 
@@ -905,25 +882,25 @@ None is passed through though.
 ValueError is also raised if one of the value in the list doesn't
 validate against the more specific marshaller.
 
-    >>> list_marshaller.marshall_from_json_data([u'Text', 1, 2])
+    >>> list_marshaller.marshall_from_json_data(['Text', 1, 2])
     Traceback (most recent call last):
       ...
-    ValueError: got 'int', expected ...: 1
+    ValueError: got 'int', expected str: 1
 
     >>> show_ValueError(choice_list_marshaller.marshall_from_request,
-    ...     [u'Vegetarian', u'NoSuchChoice'])
+    ...     ['Vegetarian', 'NoSuchChoice'])
     ValueError: Invalid value "NoSuchChoice"...
 
 ValueError is also raised if one of the keys or values in the dict doesn't
 validate against the more specific marshaller.
 
-    >>> dict_marshaller.marshall_from_json_data({1: u"Vegetarian"})
+    >>> dict_marshaller.marshall_from_json_data({1: "Vegetarian"})
     Traceback (most recent call last):
       ...
-    ValueError: got 'int', expected ...: 1
+    ValueError: got 'int', expected str: 1
 
     >>> show_ValueError(dict_marshaller.marshall_from_request,
-    ...     {u'foo': u'NoSuchChoice'})
+    ...     {'foo': 'NoSuchChoice'})
     ValueError: Invalid value "NoSuchChoice"...
 
 The return type is correctly typed to the concrete collection.
@@ -938,14 +915,14 @@ The return type is correctly typed to the concrete collection.
     [<Item Cuisine.VEGETARIAN, Vegetarian>, <Item Cuisine.DESSERT, Dessert>]
 
     >>> result = choice_list_marshaller.marshall_from_request(
-    ...     [u'Vegetarian', u'General'])
+    ...     ['Vegetarian', 'General'])
     >>> print(type(result).__name__)
     list
-    >>> pprint_list(result)
+    >>> result
     [<Item Cuisine.VEGETARIAN, Vegetarian>, <Item Cuisine.GENERAL, General>]
 
     >>> marshalled_dict = dict_marshaller.marshall_from_json_data(
-    ...     {u'foo': u'Vegetarian', u'bar': u'General'})
+    ...     {'foo': 'Vegetarian', 'bar': 'General'})
     >>> print(type(marshalled_dict).__name__)
     dict
     >>> pprint_dict(marshalled_dict)
@@ -958,16 +935,16 @@ underlying type are then followed. When marshalling dicts, the
 list elements are name,value strings which are pulled apart and
 used to populate the dict.
 
-    >>> pprint_list(list_marshaller.marshall_from_request([u'1', u'2']))
+    >>> list_marshaller.marshall_from_request(['1', '2'])
     ['1', '2']
-    >>> pprint_list(list_marshaller.marshall_from_request('["1", "2"]'))
+    >>> list_marshaller.marshall_from_request('["1", "2"]')
     ['1', '2']
 
     >>> pprint_dict(
     ...     dict_marshaller.marshall_from_request('["foo,Vegetarian"]'))
     {'foo': <Item Cuisine.VEGETARIAN, Vegetarian>}
 
-    >>> tuple_marshaller.marshall_from_request([u'1', u'2'])
+    >>> tuple_marshaller.marshall_from_request(['1', '2'])
     (1, 2)
 
 Except that 'null' still returns None.
@@ -985,7 +962,7 @@ single-element list.
     >>> tuple_marshaller.marshall_from_request('1')
     (1,)
 
-    >>> pprint_list(list_marshaller.marshall_from_request('test'))
+    >>> list_marshaller.marshall_from_request('test')
     ['test']
 
 The unmarshall() method will return a list containing the unmarshalled