align to PEP8

app.py

@@ -311,11 +311,6 @@ class GlobalSystemPrompts:
         system_prompt = f"{read_file('linguascribe.prompt')}"
         return system_prompt
 
-
-# Global variables for prompts
-system_prompt = ""
-operation_prompt = ""
-
 # Function to configure the translation mode
 def set_translation_mode(from_lang, dest_lang):
     """
@@ -325,11 +320,9 @@ def set_translation_mode(from_lang, dest_lang):
         from_lang (str): The source language.
         dest_lang (str): The destination language.
     """
-    global system_prompt
-    global operation_prompt
     system_prompt = GlobalSystemPrompts.linguascribe()
     operation_prompt = f"Translate({from_lang} to {dest_lang})"
-
+    return system_prompt, operation_prompt
 
 # List of languages supported by the application
 SUPPORTED_LANGUAGES = [
@@ -414,12 +407,14 @@ def main():
     def init_process_mode():
         """Initialize the process mode for translation if necessary."""
         if "translation" == st.session_state["process_mode"]:
-            set_translation_mode(
+            system_prompt, operation_prompt = set_translation_mode(
                 from_lang=st.session_state.language_detected,
                 dest_lang=st.session_state.target_language
             )
+            return system_prompt, operation_prompt
+        return "", ""
 
-    init_process_mode()
+    system_prompt, operation_prompt = init_process_mode()
 
     # Initialize message history with system prompt
     if "messages" not in st.session_state:
@@ -442,7 +437,7 @@ def main():
             st.session_state.target_language = cursor_selected_lang["iso-639-1"]
             
             # Initialize processing mode for current target language
-            init_process_mode()
+            system_prompt, operation_prompt = init_process_mode()
 
             # Process user message for current target language
             tts_audio, tts_duration = process_message(
@@ -487,7 +482,7 @@ def main():
             st.session_state.target_language = cursor_selected_lang["iso-639-1"]
             
             # Initialize processing mode for current target language
-            init_process_mode()
+            system_prompt, operation_prompt = init_process_mode()
             
             # Process user message for current target language
             tts_audio, tts_duration = process_message(