adding retry

src/uk/ac/ebi/vfb/neo4j/neo4j_tools.py

@@ -73,28 +73,48 @@ def __init__(self, base_uri, usr, pwd):
             if not self.test_connection():
                 raise Exception("Failed to connect to Neo4j.")
 
-    def commit_list(self, statements, return_graphs = False):
-        """Commit a list of statements to neo4J DB via REST API.
+    def commit_list(self, statements, return_graphs=False, max_retries=3):
+        """Commit a list of statements to Neo4j DB via REST API.
         Prints requests status and warnings if any problems with commit.
-            - statements = list of cypher statements as strings
-            - return_graphs, optionally specify graphs to be returned in JSON results.
-        Errors prompt warnings, not exceptions, and cause return  = FALSE.
+            - statements: list of Cypher statements as strings
+            - return_graphs: optionally specify graphs to be returned in JSON results.
+        Errors prompt warnings, not exceptions, and cause return = False.
         Returns results list of results or False if any errors are encountered."""
+
         cstatements = []
         if return_graphs:
             for s in statements:
-                cstatements.append({'statement': s, "resultDataContents" : [ "row", "graph" ]})
-        else:        
+                cstatements.append({'statement': s, "resultDataContents": ["row", "graph"]})
+        else:
             for s in statements:
-                cstatements.append({'statement': s}) # rows an columns are returned by default.
+                cstatements.append({'statement': s})  # Rows and columns are returned by default.
         payload = {'statements': cstatements}
         headers = self.headers
-        response = requests.post(url = self.base_uri + self.commit, auth = (self.usr, self.pwd) ,
-                                  data = json.dumps(payload), headers=headers)
-        if self.rest_return_check(response):
-            return response.json()['results']
-        else:
-            return False
+
+        attempt = 0
+        while attempt < max_retries:
+            try:
+                response = requests.post(
+                    url=self.base_uri + self.commit,
+                    auth=(self.usr, self.pwd),
+                    data=json.dumps(payload),
+                    headers=headers
+                )
+                if self.rest_return_check(response):
+                    return response.json()['results']
+                else:
+                    return False
+            except requests.exceptions.ConnectionError as e:
+                attempt += 1
+                print(f"ConnectionError on attempt {attempt}: {e}")
+                if attempt >= max_retries:
+                    print("Max retries reached. Operation failed.")
+                    return False
+                wait_time = 2 ** attempt  # Exponential backoff: 2, 4, 8 seconds
+                print(f"Retrying in {wait_time} seconds...")
+                time.sleep(wait_time)
+        # If all retries fail, return False
+        return False
 
 
     def commit_list_in_chunks(self, statements, verbose=False, chunk_length=1000):