Python Tutorial: Introduction to Conversational Software

Key Takeaways

hello and welcome to this course on chatbots and conversational software conversational software is not a new idea in fact the invention of the keyboard and video screen terminal brought on the first wave of command-line apps back in the 1960s to use a command line app you have to type instructions using a language that's very strict but already much closer to human language than the underlying machine instructions around the same time the iliza program was created this now-famous program was able to hold the conversation by using a rule matching engine and despite the relatively simple code behind Eliza it's actually quite a compelling conversation list in this chapter you will build your own minimal version of the Eliza chat bot in the following chapters you will learn how to use regular expressions as well as machine learning to extract meaning from freeform text you will build chat boats that can query a database plan a trip and help you order coffee you'll see that often the tricky part of building more complicated BOTS is to keep track of the state of a conversation you'll first learn techniques for avoiding this safe fulness which is usually the easiest solution later you'll learn how to handle state in the cases where you really have to in this first set of exercises you'll start with the basics the first pot you'll build is called echo bot because it simply echoes back to you whatever you say to it for simplicity all of the bots that you build in this course will receive messages in Python code and will print the responses to the screen at the end of the course we will provide you with some Python code for connecting your BOTS to various messaging apps to build an echo bot you need to define a respond function which takes a message as an argument and returns an appropriate response here we define a function using the keyword def then the name of the function then it's arguments in parentheses and then a colon the body of the function is indented by one level we specify the output generated by the function using the return keyword if a function doesn't have a return statement that means it returns a none one way we can insert variables into a string in Python is by using the strings format method inside the response function is a string containing curly brackets these acts as placeholders and will get replaced by the value of the argument we pass when we call format to keep track of everything that's being said we'll define another function called send message this prints what the user just said gets the response by calling the respond function and then prints the bots response as well even when we know we're talking to a bot it can feel a little strange to see a response come back immediately it just doesn't feel natural we can create an artificial delay by importing the time module and running time dot sleep passing the number of seconds to weight as an argument in this example we've created a half second delay now it's time for you to create your own echo bot