implemented items, to_object and zip functions

Author: Jonathan Stewmon

jmespath/compat.py

@@ -15,7 +15,9 @@ def __new__(cls, name, this_bases, d):
 if PY2:
     text_type = unicode
     string_type = basestring
+    iteritems = dict.iteritems
     from itertools import izip_longest as zip_longest
+    from itertools import imap as map
 
     def with_str_method(cls):
         """Class decorator that handles __str__ compat between py2 and py3."""
@@ -50,6 +52,8 @@ def get_methods(cls):
 else:
     text_type = str
     string_type = str
+    iteritems = dict.items
+    map = map
     from itertools import zip_longest
 
     def with_str_method(cls):

jmespath/functions.py

@@ -2,8 +2,11 @@
 import json
 
 from jmespath import exceptions
+from jmespath.compat import get_methods
+from jmespath.compat import iteritems
+from jmespath.compat import map
 from jmespath.compat import string_type as STRING_TYPE
-from jmespath.compat import get_methods, with_metaclass
+from jmespath.compat import with_metaclass
 
 
 # python types -> jmespath types
@@ -181,6 +184,10 @@ def _func_to_array(self, arg):
         else:
             return [arg]
 
+    @signature({'types': ['array']})
+    def _func_to_object(self, pairs):
+        return dict(pairs)
+
     @signature({'types': []})
     def _func_to_string(self, arg):
         if isinstance(arg, STRING_TYPE):
@@ -277,6 +284,10 @@ def _func_sort(self, arg):
     def _func_sum(self, arg):
         return sum(arg)
 
+    @signature({'types': ['object']})
+    def _func_items(self, arg):
+        return list(map(list, iteritems(arg)))
+
     @signature({"types": ['object']})
     def _func_keys(self, arg):
         # To be consistent with .values()
@@ -336,6 +347,10 @@ def _func_max_by(self, array, expref):
                                         'min_by')
         return max(array, key=keyfunc)
 
+    @signature({'types': ['array'], 'variadic': True})
+    def _func_zip(self, *arguments):
+        return list(map(list, zip(*arguments)))
+
     def _create_key_func(self, expref, allowed_types, function_name):
         def keyfunc(x):
             result = expref.visit(expref.expression, x)

tests/compliance/functions.json

@@ -12,6 +12,7 @@
     "empty_list": [],
     "empty_hash": {},
     "objects": {"foo": "bar", "bar": "baz"},
+    "pairs": [["a", "first"], ["b", "second"], ["c", "third"]],
     "null_key": null
   },
   "cases": [
@@ -171,6 +172,18 @@
       "expression": "floor(str)",
       "error": "invalid-type"
     },
+    {
+      "expression": "items(objects)",
+      "result": [["foo", "bar"], ["bar", "baz"]]
+    },
+    {
+      "expression": "items(empty_hash)",
+      "result": []
+    },
+    {
+      "expression": "items(numbers)",
+      "error": "invalid-type"
+    },
     {
       "expression": "length('abc')",
       "result": 3
@@ -185,7 +198,7 @@
     },
     {
       "expression": "length(@)",
-      "result": 12
+      "result": 13
     },
     {
       "expression": "length(strings[0])",
@@ -475,6 +488,10 @@
       "expression": "to_array(false)",
       "result": [false]
     },
+    {
+      "expression": "to_object(pairs)",
+      "result": {"a": "first", "b": "second", "c": "third"}
+    },
     {
       "expression": "to_string('foo')",
       "result": "foo"
@@ -571,6 +588,18 @@
       "expression": "not_null()",
       "error": "invalid-arity"
     },
+    {
+      "expression": "zip(strings, numbers)",
+      "result": [["a", -1], ["b", 3], ["c", 4]]
+    },
+    {
+      "expression": "zip(strings, numbers, decimals)",
+      "result": [["a", -1, 1.01], ["b", 3, 1.2], ["c", 4, -1.5]]
+    },
+    {
+      "expression": "zip(str)",
+      "error": "invalid-type"
+    },
     {
       "description": "function projection on single arg function",
       "expression": "numbers[].to_string(@)",