some clean-ups now that we require python 3.10

electrum/daemon.py

@@ -46,7 +46,7 @@ from .network import Network
 from .util import (json_decode, to_bytes, to_string, profiler, standardize_path, constant_time_compare, InvalidPassword)
 from .invoices import PR_PAID, PR_EXPIRED
 from .util import log_exceptions, ignore_exceptions, randrange, OldTaskGroup, UserFacingException, JsonRPCError
-from .util import EventListener, event_listener, traceback_format_exception
+from .util import EventListener, event_listener
 from .wallet import Wallet, Abstract_Wallet
 from .storage import WalletStorage
 from .wallet_db import WalletDB, WalletRequiresSplit, WalletRequiresUpgrade, WalletUnfinished
@@ -264,7 +264,7 @@ class AuthenticatedServer(Logger):
                 'message': "internal error while executing RPC",
                 'data': {
                     "exception": repr(e),
-                    "traceback": "".join(traceback_format_exception(e)),
+                    "traceback": "".join(traceback.format_exception(e)),
                 },
             }
         return web.json_response(response)

electrum/network.py

@@ -38,6 +38,7 @@ from concurrent import futures
 import copy
 import functools
 from enum import IntEnum
+from contextlib import nullcontext
 
 import aiorpcx
 from aiorpcx import ignore_after, NetAddress
@@ -47,7 +48,7 @@ from . import util
 from .util import (log_exceptions, ignore_exceptions, OldTaskGroup,
                    bfh, make_aiohttp_session, send_exception_to_crash_reporter,
                    is_hash256_str, is_non_negative_integer, MyEncoder, NetworkRetryManager,
-                   nullcontext, error_text_str_to_safe_str)
+                   error_text_str_to_safe_str)
 from .bitcoin import COIN, DummyAddress, DummyAddressUsedInTxException
 from . import constants
 from . import blockchain

electrum/plugin.py

@@ -127,10 +127,7 @@ class Plugins(DaemonThread):
             # sys.modules needs to be modified for relative imports to work
             # see https://stackoverflow.com/a/50395128
             sys.modules[path] = module
-            if sys.version_info >= (3, 10):
             spec.loader.exec_module(module)
-            else:
-                module = spec.loader.load_module(path)
         except Exception as e:
             raise Exception(f"Error pre-loading {path}: {repr(e)}") from e
         return module
@@ -209,12 +206,8 @@ class Plugins(DaemonThread):
                 if name in self.external_plugin_metadata:
                     raise Exception(f"duplicate plugins for name={name}")
                 module_path = f'electrum_external_plugins.{name}'
-                if sys.version_info >= (3, 10):
                 spec = zipfile.find_spec(name)
                 module = self.exec_module_from_spec(spec, module_path)
-                else:
-                    module = zipfile.load_module(name)
-                    sys.modules[module_path] = module
                 d = module.__dict__
                 gui_good = self.gui_name in d.get('available_for', [])
                 if not gui_good:

electrum/util.py

@@ -52,6 +52,7 @@ from functools import partial
 from abc import abstractmethod, ABC
 import socket
 import enum
+from contextlib import nullcontext
 
 import attr
 import aiohttp
@@ -2067,35 +2068,6 @@ def test_read_write_permissions(path) -> None:
         raise IOError('echo sanity-check failed')
 
 
-class nullcontext:
-    """Context manager that does no additional processing.
-    This is a ~backport of contextlib.nullcontext from Python 3.10
-    """
-
-    def __init__(self, enter_result=None):
-        self.enter_result = enter_result
-
-    def __enter__(self):
-        return self.enter_result
-
-    def __exit__(self, *excinfo):
-        pass
-
-    async def __aenter__(self):
-        return self.enter_result
-
-    async def __aexit__(self, *excinfo):
-        pass
-
-
-def traceback_format_exception(exc: BaseException) -> Sequence[str]:
-    """Compatibility wrapper for stdlib traceback.format_exception using python 3.10+ API."""
-    if sys.version_info[:3] >= (3, 10):
-        return traceback.format_exception(exc)
-    else:
-        return traceback.format_exception(type(exc), value=exc, tb=exc.__traceback__)
-
-
 class classproperty(property):
     """~read-only class-level @property
     from https://stackoverflow.com/a/13624858 by denis-ryzhkov

tests/qt_util.py

@@ -6,8 +6,6 @@ from unittest import SkipTest
 
 from PyQt6.QtCore import QCoreApplication, QMetaObject, Qt, pyqtSlot, QObject
 
-from electrum.util import traceback_format_exception
-
 
 class TestQCoreApplication(QCoreApplication):
     @pyqtSlot()
@@ -78,7 +76,7 @@ def qt_test(func):
             if not res:
                 self._e = Exception('testcase timed out')
             if self._e:
-                print("".join(traceback_format_exception(self._e)))
+                print("".join(traceback.format_exception(self._e)))
                 # deallocate stored exception from qt thread otherwise we SEGV garbage collector
                 # instead, re-create using the exception message, special casing AssertionError and SkipTest
                 e = None