>From 945b33bd77fae0605ae9ff9d9282ab543cb16ec8 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Fri, 14 Oct 2016 11:51:45 +0300
Subject: [PATCH 1/2] Support multi-dimensional arrays in PL/python.

Multi-dimensional arrays can now be used as arguments to a PL/python function
(used to throw an error), and they can be returned as nested Python lists.

This makes a backwards-incompatible change to the handling of composite
types in arrays. Previously, you could return an array of composite types
as "[[col1, col2], [col1, col2]]", but now that is interpreted as a two-
dimensional array. Composite types in arrays must now be returned as
Python tuples, not lists, to resolve the ambiguity. I.e. "[(col1, col2),
(col1, col2)]".

To avoid breaking backwards-compatibility, when not necessary, () is still
accepted for arrays at the top-level, but it is always treated as a
single-dimensional array. Likewise, [] is still accepted for composite types,
when they are not in an array. Update the documentation to recommend using []
for arrays, and () for composite types, with a mention that those other things
are also accepted.

This needs to be mentioned in the release notes.

Alexey Grishchenko, Dave Cramer and me.

Discussion: <CAH38_tmbqwaUyKs9yagyRra=SMaT45FPBxk1pmTYcM0TyXGG7Q@mail.gmail.com>
---
 doc/src/sgml/plpython.sgml                      |  41 +++-
 src/pl/plpython/expected/plpython_composite.out |   6 +-
 src/pl/plpython/expected/plpython_types.out     | 151 ++++++++++++-
 src/pl/plpython/expected/plpython_types_3.out   | 151 ++++++++++++-
 src/pl/plpython/plpy_typeio.c                   | 280 ++++++++++++++++++++----
 src/pl/plpython/sql/plpython_composite.sql      |   6 +-
 src/pl/plpython/sql/plpython_types.sql          |  86 ++++++++
 7 files changed, 658 insertions(+), 63 deletions(-)

diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index bb69c75..4639778 100644
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -451,13 +451,13 @@ $$ LANGUAGE plpythonu;
   <para>
    SQL array values are passed into PL/Python as a Python list.  To
    return an SQL array value out of a PL/Python function, return a
-   Python sequence, for example a list or tuple:
+   Python list:
 
 <programlisting>
 CREATE FUNCTION return_arr()
   RETURNS int[]
 AS $$
-return (1, 2, 3, 4, 5)
+return [1, 2, 3, 4, 5]
 $$ LANGUAGE plpythonu;
 
 SELECT return_arr();
@@ -467,6 +467,34 @@ SELECT return_arr();
 (1 row)
 </programlisting>
 
+   Multidimensional arrays are passed into PL/Python as nested Python lists.
+   A 2-dimensional array is a list of lists, for example. When returning
+   a multi-dimensional SQL array out of a PL/Python function, the inner
+   lists at each level must all be of the same size. For example:
+
+<programlisting>
+CREATE FUNCTION test_type_conversion_array_int4(x int4[]) RETURNS int4[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
+INFO:  ([[1, 2, 3], [4, 5, 6]], &lt;type 'list'&gt;)
+ test_type_conversion_array_int4 
+---------------------------------
+ {{1,2,3},{4,5,6}}
+(1 row)
+</programlisting>
+
+   Other Python sequences, like tuples, are also accepted for
+   backwards-compatibility with PostgreSQL versions 9.6 and below, when
+   multi-dimensional arrays were not supported. However, they are always
+   treated as one-dimensional arrays, because they are ambiguous with
+   composite types. For the same reason, when a composite type is used in a
+   multi-dimensional array, it must be represented by a tuple, rather than a
+   list.
+  </para>
+  <para>
    Note that in Python, strings are sequences, which can have
    undesirable effects that might be familiar to Python programmers:
 
@@ -541,14 +569,19 @@ CREATE TYPE named_value AS (
 CREATE FUNCTION make_pair (name text, value integer)
   RETURNS named_value
 AS $$
-  return [ name, value ]
-  # or alternatively, as tuple: return ( name, value )
+  return ( name, value )
+  # or alternatively, as tuple: return [ name, value ]
 $$ LANGUAGE plpythonu;
 </programlisting>
 
        To return a SQL null for any column, insert <symbol>None</symbol> at
        the corresponding position.
       </para>
+      <para>
+       When an array of composite types is returned, it cannot be returned as a list,
+       because it is ambiguous whether the Python list represents a composite type,
+       or another array dimension.
+      </para>
      </listitem>
     </varlistentry>
 
diff --git a/src/pl/plpython/expected/plpython_composite.out b/src/pl/plpython/expected/plpython_composite.out
index 0ef0c21..f23dccc 100644
--- a/src/pl/plpython/expected/plpython_composite.out
+++ b/src/pl/plpython/expected/plpython_composite.out
@@ -465,13 +465,13 @@ SELECT * FROM changing_test();
 
 -- tables of composite types
 CREATE FUNCTION composite_types_table(OUT tab table_record[], OUT typ type_record[] ) RETURNS SETOF record AS $$
-yield {'tab': [['first', 1], ['second', 2]],
+yield {'tab': [('first', 1), ('second', 2)],
       'typ': [{'first': 'third', 'second': 3},
               {'first': 'fourth', 'second': 4}]}
-yield {'tab': [['first', 1], ['second', 2]],
+yield {'tab': [('first', 1), ('second', 2)],
       'typ': [{'first': 'third', 'second': 3},
               {'first': 'fourth', 'second': 4}]}
-yield {'tab': [['first', 1], ['second', 2]],
+yield {'tab': [('first', 1), ('second', 2)],
       'typ': [{'first': 'third', 'second': 3},
               {'first': 'fourth', 'second': 4}]}
 $$ LANGUAGE plpythonu;
diff --git a/src/pl/plpython/expected/plpython_types.out b/src/pl/plpython/expected/plpython_types.out
index f0b6abd..5243aab 100644
--- a/src/pl/plpython/expected/plpython_types.out
+++ b/src/pl/plpython/expected/plpython_types.out
@@ -537,9 +537,133 @@ INFO:  (None, <type 'NoneType'>)
 (1 row)
 
 SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
-ERROR:  cannot convert multidimensional array to Python list
-DETAIL:  PL/Python only supports one-dimensional arrays.
-CONTEXT:  PL/Python function "test_type_conversion_array_int4"
+INFO:  ([[1, 2, 3], [4, 5, 6]], <type 'list'>)
+ test_type_conversion_array_int4 
+---------------------------------
+ {{1,2,3},{4,5,6}}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[[[1,2,NULL],[NULL,5,6]],[[NULL,8,9],[10,11,12]]]);
+INFO:  ([[[1, 2, None], [None, 5, 6]], [[None, 8, 9], [10, 11, 12]]], <type 'list'>)
+          test_type_conversion_array_int4          
+---------------------------------------------------
+ {{{1,2,NULL},{NULL,5,6}},{{NULL,8,9},{10,11,12}}}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4('[2:4]={1,2,3}');
+INFO:  ([1, 2, 3], <type 'list'>)
+ test_type_conversion_array_int4 
+---------------------------------
+ {1,2,3}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_int8(x int8[]) RETURNS int8[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_int8(ARRAY[[[1,2,NULL],[NULL,5,6]],[[NULL,8,9],[10,11,12]]]::int8[]);
+INFO:  ([[[1L, 2L, None], [None, 5L, 6L]], [[None, 8L, 9L], [10L, 11L, 12L]]], <type 'list'>)
+          test_type_conversion_array_int8          
+---------------------------------------------------
+ {{{1,2,NULL},{NULL,5,6}},{{NULL,8,9},{10,11,12}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_float4(x float4[]) RETURNS float4[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_float4(ARRAY[[[1.2,2.3,NULL],[NULL,5.7,6.8]],[[NULL,8.9,9.345],[10.123,11.456,12.6768]]]::float4[]);
+INFO:  ([[[1.2000000476837158, 2.299999952316284, None], [None, 5.699999809265137, 6.800000190734863]], [[None, 8.899999618530273, 9.345000267028809], [10.123000144958496, 11.456000328063965, 12.676799774169922]]], <type 'list'>)
+                      test_type_conversion_array_float4                       
+------------------------------------------------------------------------------
+ {{{1.2,2.3,NULL},{NULL,5.7,6.8}},{{NULL,8.9,9.345},{10.123,11.456,12.6768}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_float8(x float8[]) RETURNS float8[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_float8(ARRAY[[[1.2,2.3,NULL],[NULL,5.7,6.8]],[[NULL,8.9,9.345],[10.123,11.456,12.6768]]]::float8[]);
+INFO:  ([[[1.2, 2.3, None], [None, 5.7, 6.8]], [[None, 8.9, 9.345], [10.123, 11.456, 12.6768]]], <type 'list'>)
+                      test_type_conversion_array_float8                       
+------------------------------------------------------------------------------
+ {{{1.2,2.3,NULL},{NULL,5.7,6.8}},{{NULL,8.9,9.345},{10.123,11.456,12.6768}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_date(x date[]) RETURNS date[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_date(ARRAY[[['2016-09-21','2016-09-22',NULL],[NULL,'2016-10-21','2016-10-22']],
+            [[NULL,'2016-11-21','2016-10-21'],['2015-09-21','2015-09-22','2014-09-21']]]::date[]);
+INFO:  ([[['09-21-2016', '09-22-2016', None], [None, '10-21-2016', '10-22-2016']], [[None, '11-21-2016', '10-21-2016'], ['09-21-2015', '09-22-2015', '09-21-2014']]], <type 'list'>)
+                                                 test_type_conversion_array_date                                                 
+---------------------------------------------------------------------------------------------------------------------------------
+ {{{09-21-2016,09-22-2016,NULL},{NULL,10-21-2016,10-22-2016}},{{NULL,11-21-2016,10-21-2016},{09-21-2015,09-22-2015,09-21-2014}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_timestamp(x timestamp[]) RETURNS timestamp[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_timestamp(ARRAY[[['2016-09-21 15:34:24.078792-04','2016-10-22 11:34:24.078795-04',NULL],
+            [NULL,'2016-10-21 11:34:25.078792-04','2016-10-21 11:34:24.098792-04']],
+            [[NULL,'2016-01-21 11:34:24.078792-04','2016-11-21 11:34:24.108792-04'],
+            ['2015-09-21 11:34:24.079792-04','2014-09-21 11:34:24.078792-04','2013-09-21 11:34:24.078792-04']]]::timestamp[]);
+INFO:  ([[['Wed Sep 21 15:34:24.078792 2016', 'Sat Oct 22 11:34:24.078795 2016', None], [None, 'Fri Oct 21 11:34:25.078792 2016', 'Fri Oct 21 11:34:24.098792 2016']], [[None, 'Thu Jan 21 11:34:24.078792 2016', 'Mon Nov 21 11:34:24.108792 2016'], ['Mon Sep 21 11:34:24.079792 2015', 'Sun Sep 21 11:34:24.078792 2014', 'Sat Sep 21 11:34:24.078792 2013']]], <type 'list'>)
+                                                                                                                                                      test_type_conversion_array_timestamp                                                                                                                                                      
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{"Wed Sep 21 15:34:24.078792 2016","Sat Oct 22 11:34:24.078795 2016",NULL},{NULL,"Fri Oct 21 11:34:25.078792 2016","Fri Oct 21 11:34:24.098792 2016"}},{{NULL,"Thu Jan 21 11:34:24.078792 2016","Mon Nov 21 11:34:24.108792 2016"},{"Mon Sep 21 11:34:24.079792 2015","Sun Sep 21 11:34:24.078792 2014","Sat Sep 21 11:34:24.078792 2013"}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemint4(h int4, i int4, j int4, k int4 ) RETURNS int4[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+select pyreturnmultidemint4(8,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]]], [[[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]]]], <type 'list'>)
+                                                                                                                                                                                                                                                                             pyreturnmultidemint4                                                                                                                                                                                                                                                                              
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}}},{{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemint8(h int4, i int4, j int4, k int4 ) RETURNS int8[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+select pyreturnmultidemint8(5,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]]], [[[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]]]], <type 'list'>)
+                                                                                                                                                                                   pyreturnmultidemint8                                                                                                                                                                                    
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}}},{{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemfloat4(h int4, i int4, j int4, k int4 ) RETURNS float4[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+select pyreturnmultidemfloat4(6,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]]], [[[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]]]], <type 'list'>)
+                                                                                                                                                                                                                pyreturnmultidemfloat4                                                                                                                                                                                                                 
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}}},{{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemfloat8(h int4, i int4, j int4, k int4 ) RETURNS float8[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+select pyreturnmultidemfloat8(7,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]]], [[[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]]]], <type 'list'>)
+                                                                                                                                                                                                                                              pyreturnmultidemfloat8                                                                                                                                                                                                                                               
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}}},{{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}}}}
+(1 row)
+
 CREATE FUNCTION test_type_conversion_array_text(x text[]) RETURNS text[] AS $$
 plpy.info(x, type(x))
 return x
@@ -551,6 +675,13 @@ INFO:  (['foo', 'bar'], <type 'list'>)
  {foo,bar}
 (1 row)
 
+SELECT * FROM test_type_conversion_array_text(ARRAY[['foo', 'bar'],['foo2', 'bar2']]);
+INFO:  ([['foo', 'bar'], ['foo2', 'bar2']], <type 'list'>)
+ test_type_conversion_array_text 
+---------------------------------
+ {{foo,bar},{foo2,bar2}}
+(1 row)
+
 CREATE FUNCTION test_type_conversion_array_bytea(x bytea[]) RETURNS bytea[] AS $$
 plpy.info(x, type(x))
 return x
@@ -578,6 +709,20 @@ SELECT * FROM test_type_conversion_array_mixed2();
 ERROR:  invalid input syntax for integer: "abc"
 CONTEXT:  while creating return value
 PL/Python function "test_type_conversion_array_mixed2"
+CREATE FUNCTION test_type_conversion_mdarray_malformed() RETURNS int[] AS $$
+return [[1,2,3],[4,5]]
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_mdarray_malformed();
+ERROR:  multidimensional arrays must have array expressions with matching dimensions. PL/Python function return value has sequence length 2 while expected 3
+CONTEXT:  while creating return value
+PL/Python function "test_type_conversion_mdarray_malformed"
+CREATE FUNCTION test_type_conversion_mdarray_toodeep() RETURNS int[] AS $$
+return [[[[[[[1]]]]]]]
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_mdarray_toodeep();
+ERROR:  number of array dimensions exceeds the maximum allowed (6)
+CONTEXT:  while creating return value
+PL/Python function "test_type_conversion_mdarray_toodeep"
 CREATE FUNCTION test_type_conversion_array_record() RETURNS type_record[] AS $$
 return [{'first': 'one', 'second': 42}, {'first': 'two', 'second': 11}]
 $$ LANGUAGE plpythonu;
diff --git a/src/pl/plpython/expected/plpython_types_3.out b/src/pl/plpython/expected/plpython_types_3.out
index 56b78e1..1592219 100644
--- a/src/pl/plpython/expected/plpython_types_3.out
+++ b/src/pl/plpython/expected/plpython_types_3.out
@@ -537,9 +537,133 @@ INFO:  (None, <class 'NoneType'>)
 (1 row)
 
 SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
-ERROR:  cannot convert multidimensional array to Python list
-DETAIL:  PL/Python only supports one-dimensional arrays.
-CONTEXT:  PL/Python function "test_type_conversion_array_int4"
+INFO:  ([[1, 2, 3], [4, 5, 6]], <class 'list'>)
+ test_type_conversion_array_int4 
+---------------------------------
+ {{1,2,3},{4,5,6}}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[[[1,2,NULL],[NULL,5,6]],[[NULL,8,9],[10,11,12]]]);
+INFO:  ([[[1, 2, None], [None, 5, 6]], [[None, 8, 9], [10, 11, 12]]], <class 'list'>)
+          test_type_conversion_array_int4          
+---------------------------------------------------
+ {{{1,2,NULL},{NULL,5,6}},{{NULL,8,9},{10,11,12}}}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4('[2:4]={1,2,3}');
+INFO:  ([1, 2, 3], <class 'list'>)
+ test_type_conversion_array_int4 
+---------------------------------
+ {1,2,3}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_int8(x int8[]) RETURNS int8[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpython3u;
+SELECT * FROM test_type_conversion_array_int8(ARRAY[[[1,2,NULL],[NULL,5,6]],[[NULL,8,9],[10,11,12]]]::int8[]);
+INFO:  ([[[1, 2, None], [None, 5, 6]], [[None, 8, 9], [10, 11, 12]]], <class 'list'>)
+          test_type_conversion_array_int8          
+---------------------------------------------------
+ {{{1,2,NULL},{NULL,5,6}},{{NULL,8,9},{10,11,12}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_float4(x float4[]) RETURNS float4[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpython3u;
+SELECT * FROM test_type_conversion_array_float4(ARRAY[[[1.2,2.3,NULL],[NULL,5.7,6.8]],[[NULL,8.9,9.345],[10.123,11.456,12.6768]]]::float4[]);
+INFO:  ([[[1.2000000476837158, 2.299999952316284, None], [None, 5.699999809265137, 6.800000190734863]], [[None, 8.899999618530273, 9.345000267028809], [10.123000144958496, 11.456000328063965, 12.676799774169922]]], <class 'list'>)
+                      test_type_conversion_array_float4                       
+------------------------------------------------------------------------------
+ {{{1.2,2.3,NULL},{NULL,5.7,6.8}},{{NULL,8.9,9.345},{10.123,11.456,12.6768}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_float8(x float8[]) RETURNS float8[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpython3u;
+SELECT * FROM test_type_conversion_array_float8(ARRAY[[[1.2,2.3,NULL],[NULL,5.7,6.8]],[[NULL,8.9,9.345],[10.123,11.456,12.6768]]]::float8[]);
+INFO:  ([[[1.2, 2.3, None], [None, 5.7, 6.8]], [[None, 8.9, 9.345], [10.123, 11.456, 12.6768]]], <class 'list'>)
+                      test_type_conversion_array_float8                       
+------------------------------------------------------------------------------
+ {{{1.2,2.3,NULL},{NULL,5.7,6.8}},{{NULL,8.9,9.345},{10.123,11.456,12.6768}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_date(x date[]) RETURNS date[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpython3u;
+SELECT * FROM test_type_conversion_array_date(ARRAY[[['2016-09-21','2016-09-22',NULL],[NULL,'2016-10-21','2016-10-22']],
+            [[NULL,'2016-11-21','2016-10-21'],['2015-09-21','2015-09-22','2014-09-21']]]::date[]);
+INFO:  ([[['09-21-2016', '09-22-2016', None], [None, '10-21-2016', '10-22-2016']], [[None, '11-21-2016', '10-21-2016'], ['09-21-2015', '09-22-2015', '09-21-2014']]], <class 'list'>)
+                                                 test_type_conversion_array_date                                                 
+---------------------------------------------------------------------------------------------------------------------------------
+ {{{09-21-2016,09-22-2016,NULL},{NULL,10-21-2016,10-22-2016}},{{NULL,11-21-2016,10-21-2016},{09-21-2015,09-22-2015,09-21-2014}}}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_timestamp(x timestamp[]) RETURNS timestamp[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpython3u;
+SELECT * FROM test_type_conversion_array_timestamp(ARRAY[[['2016-09-21 15:34:24.078792-04','2016-10-22 11:34:24.078795-04',NULL],
+            [NULL,'2016-10-21 11:34:25.078792-04','2016-10-21 11:34:24.098792-04']],
+            [[NULL,'2016-01-21 11:34:24.078792-04','2016-11-21 11:34:24.108792-04'],
+            ['2015-09-21 11:34:24.079792-04','2014-09-21 11:34:24.078792-04','2013-09-21 11:34:24.078792-04']]]::timestamp[]);
+INFO:  ([[['Wed Sep 21 15:34:24.078792 2016', 'Sat Oct 22 11:34:24.078795 2016', None], [None, 'Fri Oct 21 11:34:25.078792 2016', 'Fri Oct 21 11:34:24.098792 2016']], [[None, 'Thu Jan 21 11:34:24.078792 2016', 'Mon Nov 21 11:34:24.108792 2016'], ['Mon Sep 21 11:34:24.079792 2015', 'Sun Sep 21 11:34:24.078792 2014', 'Sat Sep 21 11:34:24.078792 2013']]], <class 'list'>)
+                                                                                                                                                      test_type_conversion_array_timestamp                                                                                                                                                      
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{"Wed Sep 21 15:34:24.078792 2016","Sat Oct 22 11:34:24.078795 2016",NULL},{NULL,"Fri Oct 21 11:34:25.078792 2016","Fri Oct 21 11:34:24.098792 2016"}},{{NULL,"Thu Jan 21 11:34:24.078792 2016","Mon Nov 21 11:34:24.108792 2016"},{"Mon Sep 21 11:34:24.079792 2015","Sun Sep 21 11:34:24.078792 2014","Sat Sep 21 11:34:24.078792 2013"}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemint4(h int4, i int4, j int4, k int4 ) RETURNS int4[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpython3u;
+select pyreturnmultidemint4(8,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]]], [[[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]], [[0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7], [0, 1, 2, 3, 4, 5, 6, 7]]]], <class 'list'>)
+                                                                                                                                                                                                                                                                             pyreturnmultidemint4                                                                                                                                                                                                                                                                              
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}}},{{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}},{{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7},{0,1,2,3,4,5,6,7}}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemint8(h int4, i int4, j int4, k int4 ) RETURNS int8[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpython3u;
+select pyreturnmultidemint8(5,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]]], [[[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]], [[0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4], [0, 1, 2, 3, 4]]]], <class 'list'>)
+                                                                                                                                                                                   pyreturnmultidemint8                                                                                                                                                                                    
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}}},{{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}},{{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4},{0,1,2,3,4}}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemfloat4(h int4, i int4, j int4, k int4 ) RETURNS float4[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpython3u;
+select pyreturnmultidemfloat4(6,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]]], [[[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]], [[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]]]], <class 'list'>)
+                                                                                                                                                                                                                pyreturnmultidemfloat4                                                                                                                                                                                                                 
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}}},{{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}},{{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5},{0,1,2,3,4,5}}}}
+(1 row)
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemfloat8(h int4, i int4, j int4, k int4 ) RETURNS float8[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpython3u;
+select pyreturnmultidemfloat8(7,5,3,2);
+INFO:  ([[[[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]]], [[[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]], [[0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6], [0, 1, 2, 3, 4, 5, 6]]]], <class 'list'>)
+                                                                                                                                                                                                                                              pyreturnmultidemfloat8                                                                                                                                                                                                                                               
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {{{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}}},{{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}},{{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6},{0,1,2,3,4,5,6}}}}
+(1 row)
+
 CREATE FUNCTION test_type_conversion_array_text(x text[]) RETURNS text[] AS $$
 plpy.info(x, type(x))
 return x
@@ -551,6 +675,13 @@ INFO:  (['foo', 'bar'], <class 'list'>)
  {foo,bar}
 (1 row)
 
+SELECT * FROM test_type_conversion_array_text(ARRAY[['foo', 'bar'],['foo2', 'bar2']]);
+INFO:  ([['foo', 'bar'], ['foo2', 'bar2']], <class 'list'>)
+ test_type_conversion_array_text 
+---------------------------------
+ {{foo,bar},{foo2,bar2}}
+(1 row)
+
 CREATE FUNCTION test_type_conversion_array_bytea(x bytea[]) RETURNS bytea[] AS $$
 plpy.info(x, type(x))
 return x
@@ -578,6 +709,20 @@ SELECT * FROM test_type_conversion_array_mixed2();
 ERROR:  invalid input syntax for integer: "abc"
 CONTEXT:  while creating return value
 PL/Python function "test_type_conversion_array_mixed2"
+CREATE FUNCTION test_type_conversion_mdarray_malformed() RETURNS int[] AS $$
+return [[1,2,3],[4,5]]
+$$ LANGUAGE plpython3u;
+SELECT * FROM test_type_conversion_mdarray_malformed();
+ERROR:  multidimensional arrays must have array expressions with matching dimensions. PL/Python function return value has sequence length 2 while expected 3
+CONTEXT:  while creating return value
+PL/Python function "test_type_conversion_mdarray_malformed"
+CREATE FUNCTION test_type_conversion_mdarray_toodeep() RETURNS int[] AS $$
+return [[[[[[[1]]]]]]]
+$$ LANGUAGE plpython3u;
+SELECT * FROM test_type_conversion_mdarray_toodeep();
+ERROR:  number of array dimensions exceeds the maximum allowed (6)
+CONTEXT:  while creating return value
+PL/Python function "test_type_conversion_mdarray_toodeep"
 CREATE FUNCTION test_type_conversion_array_record() RETURNS type_record[] AS $$
 return [{'first': 'one', 'second': 42}, {'first': 'two', 'second': 11}]
 $$ LANGUAGE plpython3u;
diff --git a/src/pl/plpython/plpy_typeio.c b/src/pl/plpython/plpy_typeio.c
index 70f2e6d..56cfdd1 100644
--- a/src/pl/plpython/plpy_typeio.c
+++ b/src/pl/plpython/plpy_typeio.c
@@ -45,6 +45,8 @@ static PyObject *PLyBytes_FromBytea(PLyDatumToOb *arg, Datum d);
 static PyObject *PLyString_FromDatum(PLyDatumToOb *arg, Datum d);
 static PyObject *PLyObject_FromTransform(PLyDatumToOb *arg, Datum d);
 static PyObject *PLyList_FromArray(PLyDatumToOb *arg, Datum d);
+static PyObject *PLyList_FromArray_recurse(PLyDatumToOb *elm, int *dims, int ndim, int dim,
+						  char **dataptr_p, bits8 **bitmap_p, int *bitmask_p);
 
 /* conversion from Python objects to Datums */
 static Datum PLyObject_ToBool(PLyObToDatum *arg, int32 typmod, PyObject *plrv);
@@ -53,6 +55,9 @@ static Datum PLyObject_ToComposite(PLyObToDatum *arg, int32 typmod, PyObject *pl
 static Datum PLyObject_ToDatum(PLyObToDatum *arg, int32 typmod, PyObject *plrv);
 static Datum PLyObject_ToTransform(PLyObToDatum *arg, int32 typmod, PyObject *plrv);
 static Datum PLySequence_ToArray(PLyObToDatum *arg, int32 typmod, PyObject *plrv);
+static void PLySequence_ToArray_recurse(PLyObToDatum *elm, PyObject *list,
+							int *dims, int ndim, int dim,
+							Datum *elems, bool *nulls, int *currelem);
 
 /* conversion from Python objects to composite Datums (used by triggers and SRFs) */
 static Datum PLyString_ToComposite(PLyTypeInfo *info, TupleDesc desc, PyObject *string);
@@ -631,43 +636,105 @@ PLyList_FromArray(PLyDatumToOb *arg, Datum d)
 {
 	ArrayType  *array = DatumGetArrayTypeP(d);
 	PLyDatumToOb *elm = arg->elm;
-	PyObject   *list;
-	int			length;
-	int			lbound;
-	int			i;
+	int			ndim;
+	int		   *dims;
+	char	   *dataptr;
+	bits8	   *bitmap;
+	int			bitmask;
 
 	if (ARR_NDIM(array) == 0)
 		return PyList_New(0);
 
-	if (ARR_NDIM(array) != 1)
-		ereport(ERROR,
-				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-			  errmsg("cannot convert multidimensional array to Python list"),
-			  errdetail("PL/Python only supports one-dimensional arrays.")));
+	/* Array dimensions and left bounds */
+	ndim = ARR_NDIM(array);
+	dims = ARR_DIMS(array);
+	Assert(ndim < MAXDIM);
+
+	/*
+	 * We will iterate the Postgres array in the physical order its stored in
+	 * the datum. For 3-dimensional array the order of iteration would be the
+	 * following: first you start with [0,0,0] elements through [0,0,k], then
+	 * [0,1,0] till [0,1,k] till [0,m,k], then [1,0,0] till [1,0,k] till
+	 * [1,m,k], and so on.
+	 *
+	 * In Python, there is no multi-dimensional lists as such, but they are
+	 * represented as a list of lists. So a 3-d array of [n,m,k] element is a
+	 * list of n m-element arrays, each element of which is k-element array.
+	 * PLyList_FromArray_recurse() builds the Python list for a single
+	 * dimension, and recurses for the next inner dimension.
+	 */
+	dataptr = ARR_DATA_PTR(array);
+	bitmap = ARR_NULLBITMAP(array);
+	bitmask = 1;
+
+	return PLyList_FromArray_recurse(elm, dims, ndim, 0,
+									 &dataptr, &bitmap, &bitmask);
+}
+
+static PyObject *
+PLyList_FromArray_recurse(PLyDatumToOb *elm, int *dims, int ndim, int dim,
+						  char **dataptr_p, bits8 **bitmap_p, int *bitmask_p)
+{
+	int			i;
+	PyObject   *list;
 
-	length = ARR_DIMS(array)[0];
-	lbound = ARR_LBOUND(array)[0];
-	list = PyList_New(length);
-	if (list == NULL)
-		PLy_elog(ERROR, "could not create new Python list");
+	list = PyList_New(dims[dim]);
 
-	for (i = 0; i < length; i++)
+	if (dim < ndim - 1)
 	{
-		Datum		elem;
-		bool		isnull;
-		int			offset;
-
-		offset = lbound + i;
-		elem = array_ref(array, 1, &offset, arg->typlen,
-						 elm->typlen, elm->typbyval, elm->typalign,
-						 &isnull);
-		if (isnull)
+		/* Outer dimension. Recurse for each inner slice. */
+		for (i = 0; i < dims[dim]; i++)
 		{
-			Py_INCREF(Py_None);
-			PyList_SET_ITEM(list, i, Py_None);
+			PyObject   *sublist;
+
+			sublist = PLyList_FromArray_recurse(elm, dims, ndim, dim + 1,
+											 dataptr_p, bitmap_p, bitmask_p);
+			PyList_SET_ITEM(list, i, sublist);
 		}
-		else
-			PyList_SET_ITEM(list, i, elm->func(elm, elem));
+	}
+	else
+	{
+		/*
+		 * Innermost dimension. Fill the list with the values from the array
+		 * for this slice.
+		 */
+		char	   *dataptr = *dataptr_p;
+		bits8	   *bitmap = *bitmap_p;
+		int			bitmask = *bitmask_p;
+
+		for (i = 0; i < dims[dim]; i++)
+		{
+			/* checking for NULL */
+			if (bitmap && (*bitmap & bitmask) == 0)
+			{
+				Py_INCREF(Py_None);
+				PyList_SET_ITEM(list, i, Py_None);
+			}
+			else
+			{
+				Datum		itemvalue;
+
+				itemvalue = fetch_att(dataptr, elm->typbyval, elm->typlen);
+				PyList_SET_ITEM(list, i, elm->func(elm, itemvalue));
+				dataptr = att_addlength_pointer(dataptr, elm->typlen, dataptr);
+				dataptr = (char *) att_align_nominal(dataptr, elm->typalign);
+			}
+
+			/* advance bitmap pointer if any */
+			if (bitmap)
+			{
+				bitmask <<= 1;
+				if (bitmask == 0x100 /* (1<<8) */ )
+				{
+					bitmap++;
+					bitmask = 1;
+				}
+			}
+		}
+
+		*dataptr_p = dataptr;
+		*bitmap_p = bitmap;
+		*bitmask_p = bitmask;
 	}
 
 	return list;
@@ -864,39 +931,108 @@ static Datum
 PLySequence_ToArray(PLyObToDatum *arg, int32 typmod, PyObject *plrv)
 {
 	ArrayType  *array;
-	Datum		rv;
 	int			i;
 	Datum	   *elems;
 	bool	   *nulls;
-	int			len;
-	int			lbs;
+	int64		len;
+	int			ndim;
+	int			dims[MAXDIM];
+	int			lbs[MAXDIM];
+	int			currelem;
+	Datum		rv;
+	PyObject   *pyptr = plrv;
+	PyObject   *next;
 
 	Assert(plrv != Py_None);
 
-	if (!PySequence_Check(plrv))
-		PLy_elog(ERROR, "return value of function with array return type is not a Python sequence");
+	/*
+	 * Determine the number of dimensions, and their sizes
+	 */
+	ndim = 0;
+	len = 1;
 
-	len = PySequence_Length(plrv);
-	elems = palloc(sizeof(*elems) * len);
-	nulls = palloc(sizeof(*nulls) * len);
+	Py_INCREF(plrv);
 
-	for (i = 0; i < len; i++)
+	for (;;)
 	{
-		PyObject   *obj = PySequence_GetItem(plrv, i);
+		if (!PySequence_Check(pyptr))
+			break;
 
-		if (obj == Py_None)
-			nulls[i] = true;
-		else
+		/* composite type */
+		if (PyTuple_Check(pyptr))
+			break;
+
+		/* string */
+		if (PyString_Check(pyptr) || PyBytes_Check(pyptr) || PyUnicode_Check(pyptr))
+			break;
+
+		if (ndim == MAXDIM)
+			PLy_elog(ERROR, "number of array dimensions exceeds the maximum allowed (%d)", MAXDIM);
+
+		dims[ndim] = PySequence_Length(pyptr);
+		if (dims[ndim] < 0)
+			PLy_elog(ERROR, "cannot determine sequence length for function return value");
+
+		if (dims[ndim] > MaxAllocSize)
+			PLy_elog(ERROR, "array size exceeds the maximum allowed");
+
+		len *= dims[ndim];
+		if (len > MaxAllocSize)
+			PLy_elog(ERROR, "array size exceeds the maximum allowed");
+
+		if (dims[ndim] == 0)
 		{
-			nulls[i] = false;
-			elems[i] = arg->elm->func(arg->elm, -1, obj);
+			/* empty sequence */
+			break;
 		}
-		Py_XDECREF(obj);
+
+		ndim++;
+
+		next = PySequence_GetItem(pyptr, 0);
+		Py_XDECREF(pyptr);
+		pyptr = next;
+	}
+	Py_XDECREF(pyptr);
+
+	/*
+	 * Check for zero dimensions. This happens if the object is a tuple or a
+	 * string, rather than a list, or is not a sequence at all. We don't map
+	 * tuples or strings to arrays in general, but in the first level, be
+	 * lenient, for historical reasons. So if the object is a sequence of any
+	 * kind, treat it as a one-dimensional array.
+	 */
+	if (ndim == 0)
+	{
+		if (!PySequence_Check(plrv))
+			PLy_elog(ERROR, "return value of function with array return type is not a Python sequence");
+
+		ndim = 1;
+		len = dims[0] = PySequence_Length(plrv);
 	}
 
-	lbs = 1;
-	array = construct_md_array(elems, nulls, 1, &len, &lbs,
-							   get_base_element_type(arg->typoid), arg->elm->typlen, arg->elm->typbyval, arg->elm->typalign);
+	/*
+	 * Traverse the Python lists, in depth-first order, and collect all the
+	 * elements at the bottom level into 'elems'/'nulls' arrays.
+	 */
+	elems = palloc(sizeof(Datum) * len);
+	nulls = palloc(sizeof(bool) * len);
+	currelem = 0;
+	PLySequence_ToArray_recurse(arg->elm, plrv,
+								dims, ndim, 0,
+								elems, nulls, &currelem);
+
+	for (i = 0; i < ndim; i++)
+		lbs[i] = 1;
+
+	array = construct_md_array(elems,
+							   nulls,
+							   ndim,
+							   dims,
+							   lbs,
+							   get_base_element_type(arg->typoid),
+							   arg->elm->typlen,
+							   arg->elm->typbyval,
+							   arg->elm->typalign);
 
 	/*
 	 * If the result type is a domain of array, the resulting array must be
@@ -908,6 +1044,56 @@ PLySequence_ToArray(PLyObToDatum *arg, int32 typmod, PyObject *plrv)
 	return rv;
 }
 
+/*
+ * Helper function for PLySequence_ToArray. Traverse a Python list of lists in
+ * depth-first order, storing the elements in 'elems'.
+ */
+static void
+PLySequence_ToArray_recurse(PLyObToDatum *elm, PyObject *list,
+							int *dims, int ndim, int dim,
+							Datum *elems, bool *nulls, int *currelem)
+{
+	int			i;
+
+	if (PySequence_Length(list) != dims[dim])
+		PLy_elog(ERROR,
+				 "multidimensional arrays must have array expressions with matching dimensions. "
+				 "PL/Python function return value has sequence length %d while expected %d",
+				 (int) PySequence_Length(list), dims[dim]);
+
+	if (dim < ndim - 1)
+	{
+		for (i = 0; i < dims[dim]; i++)
+		{
+			PyObject   *sublist = PySequence_GetItem(list, i);
+
+			PLySequence_ToArray_recurse(elm, sublist, dims, ndim, dim + 1,
+										elems, nulls, currelem);
+			Py_XDECREF(sublist);
+		}
+	}
+	else
+	{
+		for (i = 0; i < dims[dim]; i++)
+		{
+			PyObject   *obj = PySequence_GetItem(list, i);
+
+			if (obj == Py_None)
+			{
+				nulls[*currelem] = true;
+				elems[*currelem] = (Datum) 0;
+			}
+			else
+			{
+				nulls[*currelem] = false;
+				elems[*currelem] = elm->func(elm, -1, obj);
+			}
+			Py_XDECREF(obj);
+			(*currelem)++;
+		}
+	}
+}
+
 
 static Datum
 PLyString_ToComposite(PLyTypeInfo *info, TupleDesc desc, PyObject *string)
diff --git a/src/pl/plpython/sql/plpython_composite.sql b/src/pl/plpython/sql/plpython_composite.sql
index 473342c..72a35c3 100644
--- a/src/pl/plpython/sql/plpython_composite.sql
+++ b/src/pl/plpython/sql/plpython_composite.sql
@@ -169,13 +169,13 @@ SELECT * FROM changing_test();
 -- tables of composite types
 
 CREATE FUNCTION composite_types_table(OUT tab table_record[], OUT typ type_record[] ) RETURNS SETOF record AS $$
-yield {'tab': [['first', 1], ['second', 2]],
+yield {'tab': [('first', 1), ('second', 2)],
       'typ': [{'first': 'third', 'second': 3},
               {'first': 'fourth', 'second': 4}]}
-yield {'tab': [['first', 1], ['second', 2]],
+yield {'tab': [('first', 1), ('second', 2)],
       'typ': [{'first': 'third', 'second': 3},
               {'first': 'fourth', 'second': 4}]}
-yield {'tab': [['first', 1], ['second', 2]],
+yield {'tab': [('first', 1), ('second', 2)],
       'typ': [{'first': 'third', 'second': 3},
               {'first': 'fourth', 'second': 4}]}
 $$ LANGUAGE plpythonu;
diff --git a/src/pl/plpython/sql/plpython_types.sql b/src/pl/plpython/sql/plpython_types.sql
index 19d920d..802dd41 100644
--- a/src/pl/plpython/sql/plpython_types.sql
+++ b/src/pl/plpython/sql/plpython_types.sql
@@ -237,7 +237,80 @@ SELECT * FROM test_type_conversion_array_int4(ARRAY[NULL,1]);
 SELECT * FROM test_type_conversion_array_int4(ARRAY[]::integer[]);
 SELECT * FROM test_type_conversion_array_int4(NULL);
 SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
+SELECT * FROM test_type_conversion_array_int4(ARRAY[[[1,2,NULL],[NULL,5,6]],[[NULL,8,9],[10,11,12]]]);
+SELECT * FROM test_type_conversion_array_int4('[2:4]={1,2,3}');
 
+CREATE FUNCTION test_type_conversion_array_int8(x int8[]) RETURNS int8[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_int8(ARRAY[[[1,2,NULL],[NULL,5,6]],[[NULL,8,9],[10,11,12]]]::int8[]);
+
+CREATE FUNCTION test_type_conversion_array_float4(x float4[]) RETURNS float4[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_float4(ARRAY[[[1.2,2.3,NULL],[NULL,5.7,6.8]],[[NULL,8.9,9.345],[10.123,11.456,12.6768]]]::float4[]);
+
+CREATE FUNCTION test_type_conversion_array_float8(x float8[]) RETURNS float8[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_float8(ARRAY[[[1.2,2.3,NULL],[NULL,5.7,6.8]],[[NULL,8.9,9.345],[10.123,11.456,12.6768]]]::float8[]);
+
+CREATE FUNCTION test_type_conversion_array_date(x date[]) RETURNS date[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_date(ARRAY[[['2016-09-21','2016-09-22',NULL],[NULL,'2016-10-21','2016-10-22']],
+            [[NULL,'2016-11-21','2016-10-21'],['2015-09-21','2015-09-22','2014-09-21']]]::date[]);
+
+CREATE FUNCTION test_type_conversion_array_timestamp(x timestamp[]) RETURNS timestamp[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_timestamp(ARRAY[[['2016-09-21 15:34:24.078792-04','2016-10-22 11:34:24.078795-04',NULL],
+            [NULL,'2016-10-21 11:34:25.078792-04','2016-10-21 11:34:24.098792-04']],
+            [[NULL,'2016-01-21 11:34:24.078792-04','2016-11-21 11:34:24.108792-04'],
+            ['2015-09-21 11:34:24.079792-04','2014-09-21 11:34:24.078792-04','2013-09-21 11:34:24.078792-04']]]::timestamp[]);
+
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemint4(h int4, i int4, j int4, k int4 ) RETURNS int4[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+
+select pyreturnmultidemint4(8,5,3,2);
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemint8(h int4, i int4, j int4, k int4 ) RETURNS int8[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+
+select pyreturnmultidemint8(5,5,3,2);
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemfloat4(h int4, i int4, j int4, k int4 ) RETURNS float4[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+
+select pyreturnmultidemfloat4(6,5,3,2);
+
+CREATE OR REPLACE FUNCTION pyreturnmultidemfloat8(h int4, i int4, j int4, k int4 ) RETURNS float8[] AS $BODY$
+m = [[[[x for x in range(h)] for y in range(i)] for z in range(j)] for w in range(k)]
+plpy.info(m, type(m))
+return m
+$BODY$ LANGUAGE plpythonu;
+
+select pyreturnmultidemfloat8(7,5,3,2);
 
 CREATE FUNCTION test_type_conversion_array_text(x text[]) RETURNS text[] AS $$
 plpy.info(x, type(x))
@@ -245,6 +318,7 @@ return x
 $$ LANGUAGE plpythonu;
 
 SELECT * FROM test_type_conversion_array_text(ARRAY['foo', 'bar']);
+SELECT * FROM test_type_conversion_array_text(ARRAY[['foo', 'bar'],['foo2', 'bar2']]);
 
 
 CREATE FUNCTION test_type_conversion_array_bytea(x bytea[]) RETURNS bytea[] AS $$
@@ -268,6 +342,18 @@ $$ LANGUAGE plpythonu;
 
 SELECT * FROM test_type_conversion_array_mixed2();
 
+CREATE FUNCTION test_type_conversion_mdarray_malformed() RETURNS int[] AS $$
+return [[1,2,3],[4,5]]
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_mdarray_malformed();
+
+CREATE FUNCTION test_type_conversion_mdarray_toodeep() RETURNS int[] AS $$
+return [[[[[[[1]]]]]]]
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_mdarray_toodeep();
+
 
 CREATE FUNCTION test_type_conversion_array_record() RETURNS type_record[] AS $$
 return [{'first': 'one', 'second': 42}, {'first': 'two', 'second': 11}]
-- 
2.9.3

