Read env var once

shotgun_api3/shotgun.py

@@ -105,6 +105,8 @@ def _is_mimetypes_broken():
 
 SG_TIMEZONE = SgTimezone()
 
+SHOTGUN_API_ENABLE_ENTITY_OPTIMIZATION = False
+
 NO_SSL_VALIDATION = False
 """
 Turns off hostname matching validation for SSL certificates
@@ -649,7 +651,11 @@ def __init__(self,
         if self.config.rpc_attempt_interval < 0:
             raise ValueError("Value of SHOTGUN_API_RETRY_INTERVAL must be positive, "
                              "got '%s'." % self.config.rpc_attempt_interval)
-
+
+        global SHOTGUN_API_ENABLE_ENTITY_OPTIMIZATION
+        if os.environ.get("SHOTGUN_API_ENABLE_ENTITY_OPTIMIZATION", "0").strip().lower() == "1":
+            SHOTGUN_API_ENABLE_ENTITY_OPTIMIZATION = True
+
         self._connection = None
 
         self.__ca_certs = self._get_certs_file(ca_certs)
@@ -4472,11 +4478,9 @@ def _translate_filters_simple(sg_filter):
 
     # Payload optimization: Do not send a full object
     # just send the `type` and `id` when combining related queries
-    enable_entity_optimization_value = os.environ.get(
-        "SHOTGUN_API_ENABLE_ENTITY_OPTIMIZATION", "0"
-    ).strip()
+    global SHOTGUN_API_ENABLE_ENTITY_OPTIMIZATION
     if (
-        enable_entity_optimization_value == "1"
+        SHOTGUN_API_ENABLE_ENTITY_OPTIMIZATION
         and condition["path"] != "id"
         and condition["relation"] in ["is", "is_not"]
         and isinstance(values[0], dict)