Python 2's forgotten annoyances

[shuttle1987]

Recently I've been updating some software that was powering a static site generator. All this was in Python 2. Over the years I've also run into people somewhat skeptical of the benefits of moving to Python 3, even as late as 2016 I was working somewhere that was making new greenfield projects in Python 2!

So there's the major things that Python 3 solves, one of the largest wins in the unicode support. However there's a lot more to it than that.

Here's some annoyances that have been mostly forgotten:

• Everything is orderable in Python 2, so something like "Abc" < None won't raise an error.
• You can do from library import * in a function in Python 2
• Boolean types didn't exists
  • You could overwrite the values of True and False with other values
• Figuring out the ordering of items in a class required nasty metaclass hacks
• int/long data types weren't unified.
• Hashes were using the older algorithms that could be denial of serviced attacked
• No language support to force keyword only arguments except to take f(*args, **kwargs) then process kwargs manually
• Print was a statement

There's probably more too, but there's some good examples of little annoyances that have mostly been resolved. The standard library has a whole bunch more of these no doubt.

[shuttle1987]

@aapeliv Should I just crank the handle and make this post before the end of the year?

A starting line might be something like: "A very obvious annoyance with Python 2 code bases is that official support is just about to end, but what about all the other smaller forgotten annoyances that existed in previous versions?"

[shuttle1987]

More annoyances included:

• the cryptography being broken in older versions (was backported to 2.7 in a special security release, TODO: find the PEP and other documentation that talked about this security release)
• Old style classes
• Lack of nice type annotations
• Hash function that could be DOSed easily
• No True and False in old versions. (True and False are still unfortunately subclasses of int even to this day, which I still think is a huge design mistake.)