PL/Python: Clean up extended error reporting docs and tests

Format the example and test code more to Python style standards.
Improve whitespace.  Improve documentation formatting.

doc/src/sgml/plpython.sgml

@@ -1341,13 +1341,15 @@ $$ LANGUAGE plpythonu;
   <title>Utility Functions</title>
   <para>
    The <literal>plpy</literal> module also provides the functions
-   <literal>plpy.debug(<replaceable>msg, **kwargs</>)</literal>,
-   <literal>plpy.log(<replaceable>msg, **kwargs</>)</literal>,
-   <literal>plpy.info(<replaceable>msg, **kwargs</>)</literal>,
-   <literal>plpy.notice(<replaceable>msg, **kwargs</>)</literal>,
-   <literal>plpy.warning(<replaceable>msg, **kwargs</>)</literal>,
-   <literal>plpy.error(<replaceable>msg, **kwargs</>)</literal>, and
-   <literal>plpy.fatal(<replaceable>msg, **kwargs</>)</literal>.
+   <simplelist>
+    <member><literal>plpy.debug(<replaceable>msg, **kwargs</>)</literal></member>
+    <member><literal>plpy.log(<replaceable>msg, **kwargs</>)</literal></member>
+    <member><literal>plpy.info(<replaceable>msg, **kwargs</>)</literal></member>
+    <member><literal>plpy.notice(<replaceable>msg, **kwargs</>)</literal></member>
+    <member><literal>plpy.warning(<replaceable>msg, **kwargs</>)</literal></member>
+    <member><literal>plpy.error(<replaceable>msg, **kwargs</>)</literal></member>
+    <member><literal>plpy.fatal(<replaceable>msg, **kwargs</>)</literal></member>
+   </simplelist>
    <indexterm><primary>elog</><secondary>in PL/Python</></indexterm>
    <function>plpy.error</function> and <function>plpy.fatal</function>
    actually raise a Python exception which, if uncaught, propagates out to
@@ -1366,35 +1368,42 @@ $$ LANGUAGE plpythonu;
   </para>
 
   <para>
-
    The <replaceable>msg</> argument is given as a positional argument.  For
    backward compatibility, more than one positional argument can be given. In
    that case, the string representation of the tuple of positional arguments
    becomes the message reported to the client.
+  </para>
+
+  <para>
    The following keyword-only arguments are accepted:
-   <literal>
-   <replaceable>detail</replaceable>, <replaceable>hint</replaceable>,
-   <replaceable>sqlstate</replaceable>, <replaceable>schema_name</replaceable>,
-   <replaceable>table_name</replaceable>, <replaceable>column_name</replaceable>,
-   <replaceable>datatype_name</replaceable> , <replaceable>constraint_name</replaceable>
-   </literal>.
+   <simplelist>
+    <member><literal>detail</literal></member>
+    <member><literal>hint</literal></member>
+    <member><literal>sqlstate</literal></member>
+    <member><literal>schema_name</literal></member>
+    <member><literal>table_name</literal></member>
+    <member><literal>column_name</literal></member>
+    <member><literal>datatype_name</literal></member>
+    <member><literal>constraint_name</literal></member>
+   </simplelist>
    The string representation of the objects passed as keyword-only arguments
    is used to enrich the messages reported to the client. For example:
 
 <programlisting>
 CREATE FUNCTION raise_custom_exception() RETURNS void AS $$
-plpy.error("custom exception message", detail = "some info about exception", hint = "hint for users")
+plpy.error("custom exception message",
+           detail="some info about exception",
+           hint="hint for users")
 $$ LANGUAGE plpythonu;
 
-postgres=# select raise_custom_exception();
-ERROR:  XX000: plpy.Error: custom exception message
+=# SELECT raise_custom_exception();
+ERROR:  plpy.Error: custom exception message
 DETAIL:  some info about exception
 HINT:  hint for users
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_custom_exception", line 2, in &lt;module&gt;
-    plpy.error("custom exception message", detail = "some info about exception", hint = "hint for users")
+  PL/Python function "raise_custom_exception", line 4, in &lt;module&gt;
+    hint="hint for users")
 PL/Python function "raise_custom_exception"
-LOCATION:  PLy_elog, plpy_elog.c:132
 </programlisting>
   </para>
 

src/pl/plpython/expected/plpython_ereport.out

 CREATE FUNCTION elog_test() RETURNS void
 AS $$
-plpy.debug('debug', detail = 'some detail')
-plpy.log('log', detail = 'some detail')
-plpy.info('info', detail = 'some detail')
+plpy.debug('debug', detail='some detail')
+plpy.log('log', detail='some detail')
+plpy.info('info', detail='some detail')
 plpy.info()
-plpy.info('the question', detail = 42);
+plpy.info('the question', detail=42);
 plpy.info('This is message text.',
-                    detail = 'This is detail text',
-                    hint = 'This is hint text.',
-                    sqlstate = 'XX000',
-                    schema_name = 'any info about schema',
-                    table_name = 'any info about table',
-                    column_name = 'any info about column',
-                    datatype_name = 'any info about datatype',
-                    constraint_name = 'any info about constraint')
-plpy.notice('notice', detail = 'some detail')
-plpy.warning('warning', detail = 'some detail')
-plpy.error('stop on error', detail = 'some detail', hint = 'some hint')
+          detail='This is detail text',
+          hint='This is hint text.',
+          sqlstate='XX000',
+          schema_name='any info about schema',
+          table_name='any info about table',
+          column_name='any info about column',
+          datatype_name='any info about datatype',
+          constraint_name='any info about constraint')
+plpy.notice('notice', detail='some detail')
+plpy.warning('warning', detail='some detail')
+plpy.error('stop on error', detail='some detail', hint='some hint')
 $$ LANGUAGE plpythonu;
 SELECT elog_test();
 INFO:  info
@@ -36,46 +36,52 @@ DETAIL:  some detail
 HINT:  some hint
 CONTEXT:  Traceback (most recent call last):
   PL/Python function "elog_test", line 18, in <module>
-    plpy.error('stop on error', detail = 'some detail', hint = 'some hint')
+    plpy.error('stop on error', detail='some detail', hint='some hint')
 PL/Python function "elog_test"
-do $$ plpy.info('other types', detail = (10,20)) $$ LANGUAGE plpythonu;
+DO $$ plpy.info('other types', detail=(10, 20)) $$ LANGUAGE plpythonu;
 INFO:  other types
 DETAIL:  (10, 20)
-do $$
+DO $$
 import time;
 from datetime import date
-plpy.info('other types', detail = date(2016,2,26))
+plpy.info('other types', detail=date(2016, 2, 26))
 $$ LANGUAGE plpythonu;
 INFO:  other types
 DETAIL:  2016-02-26
-do $$
+DO $$
 basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
-plpy.info('other types', detail = basket)
+plpy.info('other types', detail=basket)
 $$ LANGUAGE plpythonu;
 INFO:  other types
 DETAIL:  ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
 -- should fail
-do $$ plpy.info('wrong sqlstate', sqlstate='54444A') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('wrong sqlstate', sqlstate='54444A') $$ LANGUAGE plpythonu;
 ERROR:  invalid SQLSTATE code
 CONTEXT:  PL/Python anonymous code block
-do $$ plpy.info('unsupported argument', blabla='fooboo') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('unsupported argument', blabla='fooboo') $$ LANGUAGE plpythonu;
 ERROR:  'blabla' is an invalid keyword argument for this function
 CONTEXT:  PL/Python anonymous code block
-do $$ plpy.info('first message', message='second message') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('first message', message='second message') $$ LANGUAGE plpythonu;
 ERROR:  the message is already specified
 CONTEXT:  PL/Python anonymous code block
-do $$ plpy.info('first message', 'second message', message='third message') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('first message', 'second message', message='third message') $$ LANGUAGE plpythonu;
 ERROR:  the message is already specified
 CONTEXT:  PL/Python anonymous code block
 -- raise exception in python, handle exception in plgsql
 CREATE OR REPLACE FUNCTION raise_exception(_message text, _detail text DEFAULT NULL, _hint text DEFAULT NULL,
                                            _sqlstate text DEFAULT NULL,
-						_schema_name text DEFAULT NULL, _table_name text DEFAULT NULL, _column_name text DEFAULT NULL,
-						_datatype_name text DEFAULT NULL, _constraint_name text DEFAULT NULL)
+                                           _schema_name text DEFAULT NULL,
+                                           _table_name text DEFAULT NULL,
+                                           _column_name text DEFAULT NULL,
+                                           _datatype_name text DEFAULT NULL,
+                                           _constraint_name text DEFAULT NULL)
 RETURNS void AS $$
-kwargs = { "message":_message, "detail":_detail, "hint":_hint,
-			"sqlstate":_sqlstate, "schema_name":_schema_name, "table_name":_table_name,
-			"column_name":_column_name, "datatype_name":_datatype_name, "constraint_name":_constraint_name }
+kwargs = {
+    "message": _message, "detail": _detail, "hint": _hint,
+    "sqlstate": _sqlstate, "schema_name": _schema_name, "table_name": _table_name,
+    "column_name": _column_name, "datatype_name": _datatype_name,
+    "constraint_name": _constraint_name
+}
 # ignore None values - should work on Python2.3
 dict = {}
 for k in kwargs:
@@ -87,14 +93,14 @@ SELECT raise_exception('hello', 'world');
 ERROR:  plpy.Error: hello
 DETAIL:  world
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 10, in <module>
+  PL/Python function "raise_exception", line 13, in <module>
     plpy.error(**dict)
 PL/Python function "raise_exception"
 SELECT raise_exception('message text', 'detail text', _sqlstate => 'YY333');
 ERROR:  plpy.Error: message text
 DETAIL:  detail text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 10, in <module>
+  PL/Python function "raise_exception", line 13, in <module>
     plpy.error(**dict)
 PL/Python function "raise_exception"
 SELECT raise_exception(_message => 'message text',
@@ -110,7 +116,7 @@ ERROR:  plpy.Error: message text
 DETAIL:  detail text
 HINT:  hint text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 10, in <module>
+  PL/Python function "raise_exception", line 13, in <module>
     plpy.error(**dict)
 PL/Python function "raise_exception"
 SELECT raise_exception(_message => 'message text',
@@ -121,7 +127,7 @@ SELECT raise_exception(_message => 'message text',
 ERROR:  plpy.Error: message text
 HINT:  hint text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 10, in <module>
+  PL/Python function "raise_exception", line 13, in <module>
     plpy.error(**dict)
 PL/Python function "raise_exception"
 DO $$
@@ -166,10 +172,10 @@ END;
 $$;
 NOTICE:  handled exception
 DETAIL:  message:(plpy.Error: message text), detail:(detail text), hint: (hint text), sqlstate: (XX555), schema_name:(schema text), table_name:(table text), column_name:(column text), datatype_name:(datatype text), constraint_name:(constraint text)
--- the displayed context is different between Python2 and Python3,
--- but that's not important for this test
+-- The displayed context is different between Python2 and Python3,
+-- but that's not important for this test.
 \set SHOW_CONTEXT never
-do $$
+DO $$
 try:
     plpy.execute("select raise_exception(_message => 'my message', _sqlstate => 'XX987', _hint => 'some hint', _table_name => 'users_tab', _datatype_name => 'user_type')")
 except Exception, e:
@@ -179,7 +185,7 @@ $$ LANGUAGE plpythonu;
 INFO:  (119577128, None, 'some hint', None, 0, None, 'users_tab', None, 'user_type', None)
 ERROR:  plpy.SPIError: plpy.Error: my message
 HINT:  some hint
-do $$
+DO $$
 try:
     plpy.error(message  = 'my message', sqlstate = 'XX987', hint = 'some hint', table_name = 'users_tab', datatype_name = 'user_type')
 except Exception, e:

src/pl/plpython/sql/plpython_ereport.sql

 CREATE FUNCTION elog_test() RETURNS void
 AS $$
-plpy.debug('debug', detail = 'some detail')
-plpy.log('log', detail = 'some detail')
-plpy.info('info', detail = 'some detail')
+plpy.debug('debug', detail='some detail')
+plpy.log('log', detail='some detail')
+plpy.info('info', detail='some detail')
 plpy.info()
-plpy.info('the question', detail = 42);
+plpy.info('the question', detail=42);
 plpy.info('This is message text.',
-                    detail = 'This is detail text',
-                    hint = 'This is hint text.',
-                    sqlstate = 'XX000',
-                    schema_name = 'any info about schema',
-                    table_name = 'any info about table',
-                    column_name = 'any info about column',
-                    datatype_name = 'any info about datatype',
-                    constraint_name = 'any info about constraint')
-plpy.notice('notice', detail = 'some detail')
-plpy.warning('warning', detail = 'some detail')
-plpy.error('stop on error', detail = 'some detail', hint = 'some hint')
+          detail='This is detail text',
+          hint='This is hint text.',
+          sqlstate='XX000',
+          schema_name='any info about schema',
+          table_name='any info about table',
+          column_name='any info about column',
+          datatype_name='any info about datatype',
+          constraint_name='any info about constraint')
+plpy.notice('notice', detail='some detail')
+plpy.warning('warning', detail='some detail')
+plpy.error('stop on error', detail='some detail', hint='some hint')
 $$ LANGUAGE plpythonu;
 
 SELECT elog_test();
 
-do $$ plpy.info('other types', detail = (10,20)) $$ LANGUAGE plpythonu;
+DO $$ plpy.info('other types', detail=(10, 20)) $$ LANGUAGE plpythonu;
 
-do $$
+DO $$
 import time;
 from datetime import date
-plpy.info('other types', detail = date(2016,2,26))
+plpy.info('other types', detail=date(2016, 2, 26))
 $$ LANGUAGE plpythonu;
 
-do $$
+DO $$
 basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
-plpy.info('other types', detail = basket)
+plpy.info('other types', detail=basket)
 $$ LANGUAGE plpythonu;
 
 -- should fail
-do $$ plpy.info('wrong sqlstate', sqlstate='54444A') $$ LANGUAGE plpythonu;
-do $$ plpy.info('unsupported argument', blabla='fooboo') $$ LANGUAGE plpythonu;
-do $$ plpy.info('first message', message='second message') $$ LANGUAGE plpythonu;
-do $$ plpy.info('first message', 'second message', message='third message') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('wrong sqlstate', sqlstate='54444A') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('unsupported argument', blabla='fooboo') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('first message', message='second message') $$ LANGUAGE plpythonu;
+DO $$ plpy.info('first message', 'second message', message='third message') $$ LANGUAGE plpythonu;
 
 -- raise exception in python, handle exception in plgsql
 CREATE OR REPLACE FUNCTION raise_exception(_message text, _detail text DEFAULT NULL, _hint text DEFAULT NULL,
                                            _sqlstate text DEFAULT NULL,
-						_schema_name text DEFAULT NULL, _table_name text DEFAULT NULL, _column_name text DEFAULT NULL,
-						_datatype_name text DEFAULT NULL, _constraint_name text DEFAULT NULL)
+                                           _schema_name text DEFAULT NULL,
+                                           _table_name text DEFAULT NULL,
+                                           _column_name text DEFAULT NULL,
+                                           _datatype_name text DEFAULT NULL,
+                                           _constraint_name text DEFAULT NULL)
 RETURNS void AS $$
-kwargs = { "message":_message, "detail":_detail, "hint":_hint,
-			"sqlstate":_sqlstate, "schema_name":_schema_name, "table_name":_table_name,
-			"column_name":_column_name, "datatype_name":_datatype_name, "constraint_name":_constraint_name }
+kwargs = {
+    "message": _message, "detail": _detail, "hint": _hint,
+    "sqlstate": _sqlstate, "schema_name": _schema_name, "table_name": _table_name,
+    "column_name": _column_name, "datatype_name": _datatype_name,
+    "constraint_name": _constraint_name
+}
 # ignore None values - should work on Python2.3
 dict = {}
 for k in kwargs:
@@ -116,11 +122,11 @@ BEGIN
 END;
 $$;
 
--- the displayed context is different between Python2 and Python3,
--- but that's not important for this test
+-- The displayed context is different between Python2 and Python3,
+-- but that's not important for this test.
 \set SHOW_CONTEXT never
 
-do $$
+DO $$
 try:
     plpy.execute("select raise_exception(_message => 'my message', _sqlstate => 'XX987', _hint => 'some hint', _table_name => 'users_tab', _datatype_name => 'user_type')")
 except Exception, e:
@@ -128,7 +134,7 @@ except Exception, e:
     raise e
 $$ LANGUAGE plpythonu;
 
-do $$
+DO $$
 try:
     plpy.error(message  = 'my message', sqlstate = 'XX987', hint = 'some hint', table_name = 'users_tab', datatype_name = 'user_type')
 except Exception, e: