py: Implement full behaviour of dict.update(), and dict().

Add keyword args to dict.update(), and ability to take a dictionary as
argument.

dict() class constructor can now use dict.update() directly.

This patch loses fast path for dict(other_dict), but is that really
needed?  Any anyway, this idiom will now re-hash the dictionary, so is
arguably more memory efficient.

Addresses issue #647.

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/basics/dict_update.py b/tests/basics/dict_update.py
index 46d1f41b5..ab1a63304 100644
--- a/tests/basics/dict_update.py
+++ b/tests/basics/dict_update.py
@@ -8,3 +8,9 @@ print(len(d))
 d.update([(1,4)])
 print(d[1])
 print(len(d))
+
+# using keywords
+d.update(a=5)
+print(d['a'])
+d.update([(1,5)], b=6)
+print(d[1], d['b'])