Remove Python2 only code

[kdheepak]

With Python2 support being dropped in #78, code associated with Python2 syntax can be upgraded to more idiomatic Python3 syntax.

This is a tracking issue for making these changes.

[kdheepak]

This try block can be simplified to remove the except block:

pyhelics/helics/capi.py

Lines 12 to 24 in 5516142

	try:
	from typing import Dict, List, Tuple, Union, Any, cast
	JSONType = Union[
	Dict[str, Any],
	List[dict],
	]
	except ImportError:
	JSONType = None
	def cast(_, val):
	return val

[kdheepak]

In Python2, f-string syntax was not supported, and Python 2 compatible s.format() needed to be used instead, e.g.

pyhelics/helics/capi.py

Lines 1070 to 1075 in 5516142

	return """<helics.{class_name}(identifier = "{identifier}", address = "{address}") at {id}>""".format(
	class_name=self.__class__.__name__,
	identifier=identifier,
	address=address,
	id=hex(id(self)),
	)

These can be changed to using f-string syntax:

f"""<helics.{self.__class__.__name__}(identifier = "{identifier}", address = "{address}") at {hex(id(self))}>"""

[kdheepak]

I believe you don't need these at the top of the file any more:

pyhelics/helics/capi.py

Line 1 in 5516142

# -*- coding: utf-8 -*-

[kdheepak]

You can drop enum34 from the dependencies:

pyhelics/setup.py

Lines 558 to 559 in 5516142

	if sys.version_info < (3, 4):
	install_requires.append("enum34")

[nightlark]

It looks like ruff implements pyupgrade checks/fixes, so maybe we could also run this to catch some syntax related updates: https://docs.astral.sh/ruff/rules/#pyupgrade-up