From 3fbb737bb3642baa90a67977486401bb55df0ffb Mon Sep 17 00:00:00 2001
From: Mohamad Zamini <32536264+mzamini92@users.noreply.github.com>
Date: Mon, 31 Jul 2023 19:15:00 -0600
Subject: [PATCH] Update combined.py (#7541)

from my understanding, the `check_repeated_memory_variable` validator
will raise an error if any of the variables in the `memories` list are
repeated. However, the `load_memory_variables` method does not check for
repeated variables. This means that it is possible for the
`CombinedMemory` instance to return a dictionary of memory variables
that contains duplicate values. This code will check for repeated
variables in the `data` dictionary returned by the
`load_memory_variables` method of each sub-memory. If a repeated
variable is found, an error will be raised.

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---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
---
 libs/langchain/langchain/memory/combined.py | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libs/langchain/langchain/memory/combined.py b/libs/langchain/langchain/memory/combined.py
index 1c46c184d4..80316755ae 100644
--- a/libs/langchain/langchain/memory/combined.py
+++ b/libs/langchain/langchain/memory/combined.py
@@ -61,10 +61,12 @@ class CombinedMemory(BaseMemory):
         # Collect vars from all sub-memories
         for memory in self.memories:
             data = memory.load_memory_variables(inputs)
-            memory_data = {
-                **memory_data,
-                **data,
-            }
+            for key, value in data.items():
+                if key in memory_data:
+                    raise ValueError(
+                        f"The variable {key} is repeated in the CombinedMemory."
+                    )
+                memory_data[key] = value
 
         return memory_data