Modify python version check such that linters recognize it

[omer54463]

This is sort of a follow up to #2005. Currently many type checkers have a hard time recognizing all the different ways you can compare versions with sys.version_info (it's a best-effort kind of thing).

I changed the comparison and made sure that:

1. It works for both python 3 and python 2.7.
2. Mypy and Pyright both understand the comparison and skip the python 2.7 implementation.

[elicn]

Personally I like less the half-tuple comparison (i.e. (3, )).
What wrong with the current method? I don't see any problems with MyPy or Pylint on my side.

[omer54463]

Here's what I'm experiencing:

uc = unicorn.Uc(unicorn.UC_ARCH_X86, unicorn.UC_MODE_64)
reveal_type(uc) # Revealed type is "unicorn.unicorn_py2.Uc"mypy(note)

Which aligns with what Mypy claims:

Mypy supports the ability to perform Python version checks and platform checks (e.g. Windows vs Posix), ignoring code paths that won’t be run on the targeted Python version or platform. This allows you to more effectively typecheck code that supports multiple versions of Python or multiple operating systems.

More specifically, mypy will understand the use of sys.version_info and sys.platform checks within if/elif/else statements. For example:

import sys

# Distinguishing between different versions of Python:
if sys.version_info >= (3, 8):
    # Python 3.8+ specific definitions and imports
else:
    # Other definitions and imports

# Distinguishing between different operating systems:
if sys.platform.startswith("linux"):
    # Linux-specific code
elif sys.platform == "darwin":
    # Mac-specific code
elif sys.platform == "win32":
    # Windows-specific code
else:
    # Other systems

...

Mypy currently does not support more complex checks, and does not assign any special meaning when assigning a sys.version_info or sys.platform check to a variable. This may change in future versions of mypy.

[elicn]

It could make sense if we were differentiating between different minor versions, but only comparing for major version this is less readable.

[elicn]

This piece of code is redundant altogether. Python 3 never gets here anyway.

[elicn]

As mentioned above, this is less readable when comparing major version only.