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Easily Implement Python Transitions


Python Transitions: Pending State Transitions

In this Python tutorial, we will discuss how to handle pending state transitions in chatbots. We will provide a step-by-step guide along with executable sample codes and explanations.

Understanding State Transitions

State transitions play a crucial role in chatbot development. They allow the chatbot to navigate through different states or actions based on user inputs. However, in certain cases, it is necessary to briefly deviate from the conversation flow and handle specific tasks before returning to the main topic. This is where pending state transitions come into play.

Defining the Policy Rules Dictionary

To implement pending state transitions, we need to define a policy_rules dictionary. The keys of this dictionary will be tuples of the current state and the received intent, while the values will be tuples of the next state, the bot’s response, and a state for which to set a pending transition.

policy_rules = {
('INIT', 'order_intent'): ('AUTHED', 'Please provide your number.', 'PENDING'),
# more rules can be added here

In this example, we have defined a rule for when the user is in the ‘INIT’ state and tries to place an order (‘order_intent’). The next state is ‘AUTHED’, and the bot’s response is “Please provide your number.” Additionally, we have set the pending state as ‘PENDING’.

Handling Pending State Transitions

Now, let’s implement the functionality to handle pending state transitions. We will create a function called send_message() that simulates sending a message to the chatbot. It takes the current state and the user’s intent as inputs. If a pending transition is defined according to the policy_rules dictionary, it returns the next state, the bot’s response, and the pending state. Otherwise, it returns None for the pending state.

def send_message(current_state, user_intent):
if (current_state, user_intent) in policy_rules:
next_state, bot_response, pending_state = policy_rules[(current_state, user_intent)]
return next_state, bot_response, pending_state
return current_state, None, None

To demonstrate the usage of the send_message() function, we can create another function called send_messages() that sends multiple messages and handles the corresponding state transitions.

def send_messages(messages):
current_state = 'INIT'
pending_state = None
for message in messages:
user_intent = message['intent']
next_state, bot_response, pending_state = send_message(current_state, user_intent)
print(f'User: {message["text"]}')
print(f'Bot: {bot_response}')
if pending_state:
print(f'Pending state: {pending_state}')
current_state = next_state
messages = [
{'text': 'I would like to place an order.', 'intent': 'order_intent'},
{'text': 'Sure, my number is 1234567890.', 'intent': 'phone_number_intent'},
{'text': 'Can you recommend any cheap hotels?', 'intent': 'hotel_recommendation_intent'}

In this example, we have defined a list of messages that the user sends to the chatbot. The send_messages() function iterates over these messages, calls the send_message() function for each message, and updates the current state accordingly. The bot’s responses and any pending states are printed to the console.


Handling pending state transitions in chatbots allows for more flexibility and better user experiences. By defining policy rules and implementing the necessary functions, developers can easily manage pending transitions. In this tutorial, we discussed how to define the policy rules dictionary, handle pending state transitions, and provided executable sample codes for a better understanding of the concepts.