Add ParseResults.from_dict classmethod, for easy construction outside of parseString

2 files changed, 32 insertions, 3 deletions

diff --git a/CHANGES b/CHANGES
index cee1b99..f02d2e7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,8 +2,8 @@
 Change Log
 ==========
 
-Version 2.4.1 -
-----------------------
+Version 2.4.1 - July, 2019
+--------------------------
 - A new shorthand notation has been added for repetition
   expressions: expr[min, max], with '...' valid as a min
   or max value:
@@ -58,6 +58,12 @@ Version 2.4.1 -
 
   This form is only valid when used with the '|' operator.
 
+- Added ParseResults.from_dict classmethod, to simplify creation
+  of a ParseResults with results names. May be called with a dict
+  argument, or with a series of named arguments (or both). This
+  makes it easy to add a sub-level of named items to the parsed
+  tokens in a parse action.
+
 - While investigating issue #93, I found that Or and
   addCondition could interact to select an alternative that
   is not the longest match. This is because Or first checks
diff --git a/pyparsing.py b/pyparsing.py
index 3d42289..27df353 100644
--- a/pyparsing.py
+++ b/pyparsing.py
@@ -96,7 +96,7 @@ classes inherit from. Use the docstrings for examples of how to:
 """
 
 __version__ = "2.4.1"
-__versionTime__ = "05 Jul 2019 23:23 UTC"
+__versionTime__ = "07 Jul 2019 06:35 UTC"
 __author__ = "Paul McGuire <ptmcg@users.sourceforge.net>"
 
 import string
@@ -112,6 +112,7 @@ import traceback
 import types
 from datetime import datetime
 from operator import itemgetter
+import itertools
 
 try:
     # Python 3
@@ -1110,6 +1111,28 @@ class ParseResults(object):
     def __dir__(self):
         return (dir(type(self)) + list(self.keys()))
 
+    @classmethod
+    def from_dict(cls, other=None, **kwargs):
+        """
+        Helper classmethod to construct a ParseResults from either a dict or a sequence of named arguments,
+        preserving the name-value relations as results names.
+        """
+        if other is not None:
+            items = itertools.chain(other.items(), kwargs.items())
+        else:
+            items = kwargs.items()
+
+        def is_iterable(obj):
+            try: iter(obj)
+            except Exception: return False
+            else:
+                if PY_3:
+                    return not isinstance(obj, (str, bytes))
+                else:
+                    return not isinstance(obj, basestring)
+
+        return sum(cls([v], name=k, asList=is_iterable(v)) for k, v in items)
+
 MutableMapping.register(ParseResults)
 
 def col (loc,strg):