Asterisk Python Module Pyst

Using the Asterisk Python Module "Pyst"

The Asterisk Python module "Pyst" provides a simplified way to interact with Asterisk, an open-source framework for building communications applications, including VoIP gateways, conference servers, and more. "Pyst" enables Python developers to automate and manage Asterisk functionalities, integrating them into Python-based applications. This document explores the history, features, and usage of the Pyst module.

There was pyst2, then pyst3, and now it is pyst. The Short History

The evolution of the Pyst module reflects the broader transition within the Python ecosystem from Python 2 to Python 3:

• Pyst2: Initially, Pyst was developed to work with Python 2, leveraging its capabilities to connect and control Asterisk servers. Its initial iterations aimed at providing basic functionalities like call initiation, monitoring, and terminations.

• Pyst3: With the advent of Python 3, "Pyst2" was updated and rebranded as "Pyst3" to ensure compatibility with the newer Python version. This version included enhancements such as improved syntax, better error handling, and more efficient performance to match Python 3’s capabilities.

• Pyst: As both Python and Pyst matured, the sequential naming was dropped in favor of a unified module simply named "Pyst". This version is designed to work seamlessly with the latest Python releases while also maintaining backward compatibility with previous Pyst functionalities. The move symbolizes a stabilized API and user experience.

Simple Asterisk Dialplan Example

Asterisk uses dialplans as a scripting language to handle call processing logic. Here is a simple example of an Asterisk dialplan:

[default]
exten => 100,1,Answer()
 same => n,Playback(hello-world)
 same => n,Hangup()

This dialplan does the following:

• Answers a call to extension 100.
• Plays a pre-recorded message "hello-world".
• Hangs up the call.

Using the Asterisk Python Module "Pyst", and It Is import asterisk Not import pyst

Contrary to what the module name might suggest, when using the "Pyst" module in a Python script, you need to import it using import asterisk. This naming convention aligns with Python's common practice of naming modules after their primary functionality or the core library they interact with.

import asterisk.ami

# Create a connection to the Asterisk server
client = asterisk.ami.AMIClient(address='127.0.0.1', port=5038)
client.login(username='admin', secret='yourpassword')

# Event listener
def on_event(event):
    print(f"Received event: {event}")

client.add_event_listener(on_event)

# Send a simple command to the Asterisk server
response = client.send_action({'Action': 'Ping'})

print(f"Response: {response.response}")

client.logoff()

In this example:

• The asterisk.ami.AMIClient class is used to establish a connection to an Asterisk server using the Asterisk Manager Interface (AMI).
• We define an event listener that prints received events to the console.
• The Ping action checks connectivity with the server.

This illustrates how the "Pyst" module can facilitate remote control and monitoring of Asterisk servers, simplifying the process of integrating telephony features into Python applications.