Fixes for Python 3.9 (#78)

* Update queue.py

* make PipelineException iterable

* pump version

* another exception instance

* blackify

pypeln/process/queue.py

@@ -13,9 +13,7 @@
 T = tp.TypeVar("T")
 
 
-class PipelineException(tp.NamedTuple, BaseException):
-    exception: tp.Optional[tp.Type[BaseException]]
-    trace: str
+PipelineException = pypeln_utils.PipelineException
 
 
 class IterableQueue(Queue, tp.Generic[T], tp.Iterable[T]):

pypeln/task/queue.py

@@ -13,9 +13,7 @@
 T = tp.TypeVar("T")
 
 
-class PipelineException(tp.NamedTuple, BaseException):
-    exception: tp.Optional[tp.Type[BaseException]]
-    trace: str
+PipelineException = pypeln_utils.PipelineException
 
 
 class IterableQueue(asyncio.Queue, tp.Generic[T], tp.Iterable[T]):

pypeln/thread/queue.py

@@ -1,9 +1,7 @@
 import sys
-import time
 import traceback
 import typing as tp
 from queue import Queue, Empty, Full
-from threading import Lock
 
 from pypeln import utils as pypeln_utils
 
@@ -12,9 +10,7 @@
 T = tp.TypeVar("T")
 
 
-class PipelineException(tp.NamedTuple, BaseException):
-    exception: tp.Optional[tp.Type[BaseException]]
-    trace: str
+PipelineException = utils.pypeln_utils.PipelineException
 
 
 class IterableQueue(Queue, tp.Generic[T], tp.Iterable[T]):

pypeln/utils.py

@@ -2,6 +2,7 @@
 import inspect
 import sys
 import typing as tp
+import dataclasses
 
 if sys.version_info >= (3, 8):
     from typing import Protocol, runtime_checkable
@@ -17,6 +18,27 @@
 B = tp.TypeVar("B")
 
 
+@dataclasses.dataclass
+class PipelineException(BaseException):
+    exception: tp.Optional[tp.Type[BaseException]]
+    trace: str
+
+    def __iter__(self):
+        self.n = 0
+        return self
+
+    def __next__(self):
+        # Workaround to make PipelineException act more like the
+        # namedtuple it was designed to be
+        try:
+            item = {0: self.exception, 1: self.trace}[self.n]
+        except KeyError as e:
+            raise StopIteration from e
+
+        self.n += 1
+        return item
+
+
 class NoLock(Exception):
     pass
 

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "pypeln"
-version = "0.4.7"
+version = "0.4.8"
 description = ""
 authors = ["Cristian Garcia <[email protected]>"]
 license = "MIT"