Adventures in Machine Learning

Python 311’s New Features: Task and Exception Groups for Cleaner Code

Python 3.11 Alpha: A Preview of Exciting New Features

Python, one of the most popular programming languages, is about to receive an update that developers are eagerly anticipating. Python 3.11 Alpha, the first pre-release version, is available for testing and experimentation before the official launch.

In this article, we’ll take a look at the new features being introduced in Python 3.11 and explore how to install and run this update on your machine. Overview of New Features in Python 3.11

Python has a steady and dedicated user base that has helped drive the development of new features, making the language more versatile and user-friendly.

Python 3.11 comes packed with several new features that aim to improve performance, simplify code, and reduce development time. One of the most exciting new features in Python 3.11 is the introduction of task and exception groups.

These groups provide a way for developers to better manage their code by grouping tasks together and handling exceptions uniformly. For example, if a group of tasks is dependent on another task, these could be grouped together and handled in a more synchronized fashion.

This will help developers write cleaner and more efficient code, reducing the possibility of bugs and reducing code complexity. Python 3.11 also introduces better support for structural pattern matching.

This will allow developers to write clear, concise, and understandable code, especially when dealing with complex data structures. Improved support for numeric literals and improved input/output operations further enhances the programming experience.

Preview of Task and Exception Groups

Task and exception groups are among the most exciting new features of Python 3.11. They allow developers to write cleaner code, minimizing the need for boilerplate code and reducing the chances for bugs.

Task groups enable developers to group tasks based on their dependencies and handle them uniformly, which is particularly useful in scenarios where complex tasks need to be executed with a clear sense of order. Exception groups offer a new way of handling exceptions uniformly.

By categorizing exceptions into groups, developers can write code that catches exceptions and handles them in a uniform way for a given group. This ensures that the codebase is uniform and follows best practices, making it easy to catch bugs and fix issues.

Importance of Managing Exceptions

Managing exceptions plays a crucial role in maintaining the efficiency and security of a Python program. Whether handling unexpected input values or writing error-free code, by handling exceptions uniformly, programmers can ensure that their code works as intended and that any errors are handled correctly.

By dealing with exceptions in a uniform way, developers can create code that is much easier to debug and maintain. This helps them save time and effort in the long-term while making their code more understandable and efficient.

It’s important to invest time in managing exceptions in Python 3.11 to take advantage of its excellent error-handling features.


To test out Python 3.11, it’s essential to have it installed on your machine. Here are a few ways of installing Python 3.11.

1. Docker installation: Docker provides an easy way to install and run Python 3.11 on your machine.

You can use Docker to run Python in a containerized environment, which allows you to test your code without worrying about versioning issues. 2.

Using pyenv to install and set up virtual environment: Pyenv is a simple yet powerful tool that makes it easy to install, switch between, and manage multiple versions of Python. You can use pyenv to create a virtual environment that matches the new Python 3.11 installation.

3. Installing from pre-release versions on If you’re comfortable with working with pre-release versions of software, you can download Python 3.11 from and install it using the traditional method of compiling the source code.

Running Code Examples in Python 3.11

Once you have installed Python 3.11 on your machine, it’s time to test it out! You can experiment with the new features by writing code and running it in the Python environment. Here’s a simple example of using task groups in Python 3.11:


from asyncio import create_task, gather

async def task_one():

print(“Task One Executed”)

async def task_two():

print(“Task Two Executed”)

async def task_group():

tasks = [create_task(task_one()), create_task(task_two())]

await gather(*tasks)

await task_group()


The code above creates two tasks (task_one and task_two) and a task group (task_group), which includes both tasks. The gather function ensures that both tasks are executed before moving on to the next task in the group.

This simple example demonstrates how task groups can be used to manage dependent tasks. In conclusion, Python 3.11 Alpha introduces some exciting new features that will make the programming experience more efficient, cleaner, and more enjoyable.

By using task and exception groups, developers can write better-organized code, reduce the chance of bugs, and maintain an efficient workflow. Installing and running Python 3.11 is straightforward, and you can experiment with the new features using simple code examples.

Give Python 3.11 a go, and let us know what you think!

Exception Groups and except* in Python 3.11

Python’s error-handling features have always been a significant selling point for the language. Developers rely on Python’s precise and informative error messages for debugging purposes.

The latest version of Python, 3.11, brings in some new and powerful features for handling exceptions. In this article, we’ll discuss Exception Groups and the except* syntax, which help simplify the error-handling process.

Exception Handling in Python

In Python, exceptions are a way of detecting and handling errors that occur during program execution. When an error occurs, Python generates an exception object, which can be caught and handled by the code.

There are two types of exceptions; built-in and user-defined. Built-in exceptions are defined in the Python language itself, whereas user-defined exceptions are custom-made by the developers to handle specific code functionality.

An example of a built-in exception is the ZeroDivisionError, which Python raises when an attempt is made to divide by zero. An example of a user-defined exception in Python is the InvalidInputError which can be used to handle situations when incorrect data is passed to a Chaining Related Exceptions

Chaining exceptions is a powerful feature of Python’s exception-handling mechanism.

Chaining related exceptions help developers to trace the root cause of an error quickly. The new syntax for exception handling in Python 3.11, called except*, makes chaining exceptions even easier.

When an exception is caught in Python, the traceback provides information about where the error occurred in the program. This traceback can be inspected to determine the cause of the error.

Chaining allows multiple exceptions to be raised consecutively, each indicating where the error was detected before the final exception is raised.

ExceptionGroup class

Python 3.11 introduces the

ExceptionGroup class, which simplifies the handling of related exceptions. The

ExceptionGroup class creates a group of exceptions as one entity.

Each exception within the group propagates up the call stack, and the group as a whole is only caught by an except* block. Whenever an exception is raised, the traceback includes the entire group, making it easier to identify errors and the cause of the error.

Creating and Formatting Exception Groups

An ExceptionGroup can be created using the

ExceptionGroup class. Here is a simple example of creating an ExceptionGroup:


from types import ExceptionGroup


# some code that raises an exception

raise ValueError(“A ValueError occurred”)

except ExceptionGroup as group:

print(f”Caught an Exception Group containing {len(group.exceptions)} exceptions”)

for e in group.exceptions:

print(f” – {type(e).__name__}: {str(e)}”)


In the example code above, if a ValueError is raised, the exception is captured and added to the ExceptionGroup. The traceback for the ExceptionGroup includes every exception added to it as well as their order.

This makes it much easier to determine the cause of the error. Regular except Blocks Versus except* Syntax

In Python, exceptions can be handled using the except block.

It can catch an exception of a specific type or all types of exceptions, as shown in the example below. “`


# some code that raises an exception

raise ValueError(“A ValueError occurred”)

except ValueError as ve:

print(f”Caught ValueError: {str(ve)}”)


print(“Caught something else other than ValueError.”)


In the example code above, the except block is used to handle the ValueError exception.

Since the second except block does not specify the exception type, it will catch all exceptions that are not caught by previous except blocks in the same try block. In Python 3.11, the except* syntax simplifies the process of catching related exceptions.

This syntax requires only one except block that catches a group of exceptions. “`

from types import ExceptionGroup


# some code that raises exceptions

raise ValueError(“A ValueError occurred”)

raise KeyError(“A KeyError occurred”)

except ExceptionGroup as ge:

print(f”Caught {len(ge.exceptions)} exceptions”)

for e in ge.exceptions:

print(f” – {type(e).__name__}: {str(e)}”)


In this example code, the except block catches every exception raised within the try block. The traceback of these exceptions includes all the exceptions raised, making it easier to identify the root cause of the error.

Handle Regular Exceptions With except

Raising and handling exceptions is a fundamental part of Python programming. In Python 3.11, the new

ExceptionGroup class and except* syntax have made the error-handling process even more efficient and straightforward.

In Python, exceptions are raised by using the raise statement. The raise statement is used to throw an exception manually and includes a parameter that indicates the exception to be raised.

An except block may be used to catch exceptions, as discussed above. Python’s exception hierarchy allows for specific exceptions to be caught by a general exception.

This helps catch exceptions that are related to each other. Exception chaining is used when multiple exceptions are raised to create a chain of related exceptions.

The “raise from” statement is used to chain exceptions, which helps identify the route of the error. In conclusion, Exception Groups and the except* syntax are among the many new features introduced in Python 3.11, which make the error-handling process smooth and efficient.

By creating and formatting Exception Groups, Python developers now have a convenient way to manage related exceptions in their code. On the other hand, except* simplifies the exceptions handling process by catching all exceptions raised within the try block in one go.

Moreover, Python’s exception hierarchy and chaining related exceptions provide clear and precise error messages that make debugging a breeze.

Group Exceptions with ExceptionGroup


ExceptionGroup class helps developers manage related exceptions easily. In this article, we’ll explore how to create ExceptionGroups with sub-exceptions, tracebacks formatting, and how to catch exception groups with regular except blocks.

We’ll also delve into the limitations of regular except blocks when handling ExceptionGroups.

Creating Exception Groups with Sub-Exceptions

An ExceptionGroup with sub-exceptions consists of multiple related exceptions under a single parent exception. The sub-exceptions allow for developers to gather and manage exceptions that are contiguous in their code.


from types import ExceptionGroup


i = int(‘String’)

except Exception as e:

data1 = AttributeError(‘Invalid data’)

data2 = ValueError(str(e))

exc_group = ExceptionGroup(” Invalid data error”, [data2, data1])

raise exc_group from e


In the above code snippet, we convert a string to an integer by using the int() function. When this line of code executes, the ValueError is generated because ‘String’ cannot be converted to an integer.

We can fill in more details about the error by adding two new exceptions to the ExceptionGroup data1 and data2. Then the raise statement is used to propagate the ExceptionGroup to the parent handle.

Traceback Formatting for Exception Groups

When re-raising an ExceptionGroup, Pyhton 3.11 provides a detailed traceback message, along with the original exception. The traceback information shows the name of the ExceptionGroup, the parent exception, and the sub-exceptions.

This advanced traceback helps developers identify the exact location and type of error(s) that occur in the code.

Catching Exception Groups with Regular except Blocks

Python’s try-except block is used to handle exceptions. A developer can either handle a specific exception or a groups of exceptions with the except, or except* syntax respectively.

However, regular except blocks can be used to catch ExceptionGroups. The code snippet below demonstrates this functionality.



# code that generates ExceptionGroups

except Exception as exc:

if isinstance(exc, ExceptionGroup):

for subexc in exc:

# Handle the sub-exceptions


# Handle the exception normally


In the code snippet, the try block tries to execute a code segment that may generate an ExceptionGroup. If the code generates an ExceptionGroup, the except block acknowledges it as an ExceptionGroup instance and handles the sub-exceptions.

Otherwise, it handles the exception normally.

Limitations of Regular except Blocks for ExceptionGroups

Though regular except blocks could catch exception groups, they have some limitations. The primary limitation is that it doesn’t inform developers of the nature of the exception(s) when caught.

When you catch an ExceptionGroup with a typical except block, you have no idea of the number of sub-exceptions inside the group object and the exact reason(s) for its existence.

Filter Exceptions with except*

Previously, a developer had to define multiple code sections to handle a specific exception type or user-defined exception.

However, now there is an easier way to filter out a group of exceptions: by using the except* syntax.

Benefits of except* Syntax for Exception Groups

The except* syntax is a new addition to Python 3.11.

The syntax enables developers to catch all exceptions in an ExceptionGroup with a single line of code. The except * block catches all the associated Exceptions in the group and handles them uniformly.

This functionality makes the code more concise, readable, and easier to manage.

Attributes and Methods of Exception Groups


ExceptionGroup class provides various methods and attributes suited for exception-handling scenarios. Here are a few of them:

– exceptions: It provides a tuple containing all sub-exceptions contained in the ExceptionGroup instance.

– name: Displays the name of the ExceptionGroup object. – message: displays the original exception message

– traceback: displays the complete traceback of the ExceptionGroup, including the sub-exceptions.

Handling Exception Groups with except* Syntax

Here’s an example of how to use the except* syntax to handle an ExceptionGroup:


from types import ExceptionGroup


# code that generates ExceptionGroups

except ExceptionGroup as exc_grp:

print(exc_grp, exc_grp.exceptions)

except Exception as exc:



In the example snippet above, the developer attempted to execute code that might generate an ExceptionGroup. If this occurs, the except exception group catches it, displays the group object, then the individual sub-exceptions.

In conclusion, Python 3.11’s

ExceptionGroup class and except* syntax are game changers in Python’s exception-handling functionality. Developers can now manage, capture, and report related exceptions uniformly by using the ExceptionGroup object.

The except* syntax reduces the need for code redundancy when filtering exceptions. Understanding the attributes and methods of ExceptionGroups helps in debugging and maintaining Python code.

Asynchronous Task Groups in Python 3.11

Python 3.11 incorporates many new features that make it a powerful programming language. One of the most significant updates is the introduction of asynchronous code.

In this piece, we will discuss asynchronous code and Python’s asyncio library, which facilitates efficient concurrent programming for heavy computational tasks. We’ll also go through how to use task groups to manage these tasks.

Advantages of Asynchronous Code

Computational tasks can take a lot of time to execute and are usually computationally intensive. Asynchronous code

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