Python 3.10 is released! You should know these 5 new features

Python has been in the market for a while now, and as a Python developer, I am happy to share that Python is gradually getting updates and improvements with each new version. The latest version of Python, 3.10, has some major improvements, and I'll list those updates here. I've listed the first 5 updates for this new version.

1. Improvements in error messages

For Python developers, when you write code and encounter an error, error messages can help you find the error in the code. Improved error messages make your life easier than when using previous Python versions. For example, consider the following code, where there are no brackets at the end of the second line:

# In previous versions - Python 3.9 and earlier, you would see the following Error -

Well, invalid syntax! Now, as a developer, what do you understand from this error message? Well, personally, I don't understand anything except the fact that somewhere on line 3 I added wrong syntax.

But, does the error really appear on line 3? Python 3.10 is the savior in this case, with the latest updates. For the same piece of code, Python 3.10 will throw the following error message -

The line number and very specific error message will allow you to jump right in, fix the error, and continue coding! Another example of my personal attempt to see if the error message is clear enough -

This is really a cool update in the Python 3.10 version, please leave a comment on this article Share your thoughts on this section.

2. Simpler type union syntax

In past Python versions, more tools have moved from type conversion to built-in functions to avoid importing static types every time. Now look at this change -

In Python 3.10, you are now allowed to use the pipe operator (|) to specify type unions instead of from the input module Import union. In addition, the existing typing.Union and | syntax should be equivalent, as compared with the following -

3. Use multiple `with` statements in multiple lines

Python does support multi-line statements through the use of backslash(), but some constructs in Python do not require the use of slashes to write multi-line statements. One of them is a context manager with a multi-line with() statement. For example -

Yes, this may not seem like a feature, but it is a significant improvement over previous versions as you may have encountered using multi-line context managers use case, but failed to execute due to the above error. If you're still confused, let's give some more examples of what you can do with the Python 3.10 version of the context manager -

You can now have multi-line contexts manager statement without using backslashes. Great, right?

4. Better type aliases

Type aliases allow you to quickly define new aliases that can be created for complex type declarations. For example -

This usually works fine. However, it is usually impossible for a type checker to know whether such a statement is a type alias or just a definition of a regular global variable.

The above python code declares an alias UserInfo for tuple[str, str] because it is a data type that combines values ​​of multiple types. In our case it's a string and an integer. Additionally, adding TypeAlias ​​annotations clarifies intent to the type checker and anyone reading your code.

5. Stricter sequence compression

zip() is a built-in function in Python that you may have used when combining multiple lists/sequences. Python 3.10 introduces the new strict parameter, which adds a runtime test to check that all compressed sequences have the same length. For example -

zip() can be used to iterate these three lists in parallel:

Let’s use the above again The names and numbers of the two sequences are displayed. Now the only difference is that the numbers between these sequences are different lengths of the sequence names as shown below -

Note that all the information about the name - Kevin Gone! If your data set is larger, it will be harder to find such errors. Even if you find a problem, diagnosing and fixing it isn't always easy. The assumption that the compressed sequences will be of the same length not only helps you avoid this discrepancy. In Python 3.10, the strict parameter can help you avoid this situation in the first place -

While strict doesn't really add any new functionality to zip(), It helps you avoid those hard-to-find mistakes.

Other updates in Python 3.10 This version has a lot of bug fixes as well as some other small updates, which can be found on the official release page if you are interested.

Original text: https://varun-singh-01.medium.com/python-3-10-released-top-5-new-features-you-should-know-bf968ac99230

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