.catch: accept multiple exception types (closes #58) (#68)

streamable/functions.py

@@ -57,17 +57,18 @@
 def catch(
     iterator: Iterator[T],
     kind: Type[Exception] = Exception,
-    when: Callable[[Exception], Any] = bool,
+    *others: Type[Exception],
+    when: Optional[Callable[[Exception], Any]] = None,
     replacement: T = NO_REPLACEMENT,  # type: ignore
     finally_raise: bool = False,
 ) -> Iterator[T]:
     validate_iterator(iterator)
     return CatchIterator(
         iterator,
-        kind,
+        (kind, *others),
         when,
         replacement,
-        finally_raise=finally_raise,
+        finally_raise,
     )
 
 

streamable/iterators.py

@@ -62,15 +62,15 @@ class CatchIterator(Iterator[T]):
     def __init__(
         self,
         iterator: Iterator[T],
-        kind: Type[Exception],
-        when: Callable[[Exception], Any],
+        kinds: Tuple[Type[Exception], ...],
+        when: Optional[Callable[[Exception], Any]],
         replacement: T,
         finally_raise: bool,
     ) -> None:
         validate_iterator(iterator)
         self.iterator = iterator
-        self.kind = kind
-        self.when = wrap_error(when, StopIteration)
+        self.kinds = kinds
+        self.when = wrap_error(when, StopIteration) if when else None
         self.replacement = replacement
         self.finally_raise = finally_raise
         self._to_be_finally_raised: Optional[Exception] = None
@@ -85,8 +85,8 @@ def __next__(self) -> T:
                     self._to_be_finally_raised = None
                     raise exception
                 raise
-            except Exception as exception:
-                if isinstance(exception, self.kind) and self.when(exception):
+            except self.kinds as exception:
+                if not self.when or self.when(exception):
                     if self._to_be_finally_raised is None:
                         self._to_be_finally_raised = exception
                     if self.replacement is not NO_REPLACEMENT:

streamable/stream.py

@@ -115,23 +115,32 @@ def accept(self, visitor: "Visitor[V]") -> V:
     def catch(
         self,
         kind: Type[Exception] = Exception,
-        when: Callable[[Exception], Any] = bool,
+        *others: Type[Exception],
+        when: Optional[Callable[[Exception], Any]] = None,
         replacement: T = NO_REPLACEMENT,  # type: ignore
         finally_raise: bool = False,
     ) -> "Stream[T]":
         """
-        Catches the upstream exceptions if they are instances of `kind` and they satisfy the `when` predicate.
+        Catches the upstream exceptions if they are instances of `kind` (or `others`) and they satisfy the `when` predicate.
 
         Args:
-            kind (Type[Exception], optional): The type of exceptions to catch. (default: catches base Exception)
-            when (Callable[[Exception], Any], optional): An additional condition that must be satisfied to catch the exception, i.e. `when(exception)` must be truthy. (default: no additional condition)
+            kind (Type[Exception], optional): The type of exceptions to catch. (default: catches `Exception`)
+            *others (Type[Exception], optional): Additional types of exceptions to catch.
+            when (Optional[Callable[[Exception], Any]], optional): An additional condition that must be satisfied to catch the exception, i.e. `when(exception)` must be truthy. (default: no additional condition)
             replacement (T, optional): The value to yield when an exception is catched. (default: do not yield any replacement value)
             finally_raise (bool, optional): If True the first catched exception is raised when upstream's iteration ends. (default: iteration ends without raising)
 
         Returns:
             Stream[T]: A stream of upstream elements catching the eligible exceptions.
         """
-        return CatchStream(self, kind, when, replacement, finally_raise)
+        return CatchStream(
+            self,
+            kind,
+            *others,
+            when=when,
+            replacement=replacement,
+            finally_raise=finally_raise,
+        )
 
     def count(self) -> int:
         """
@@ -540,12 +549,14 @@ def __init__(
         self,
         upstream: Stream[T],
         kind: Type[Exception],
-        when: Callable[[Exception], Any],
+        *others: Type[Exception],
+        when: Optional[Callable[[Exception], Any]],
         replacement: T,
         finally_raise: bool,
     ) -> None:
         super().__init__(upstream)
         self._kind = kind
+        self._others = others
         self._when = when
         self._replacement = replacement
         self._finally_raise = finally_raise

streamable/visitors/iterator.py

@@ -30,8 +30,9 @@ def visit_catch_stream(self, stream: CatchStream[T]) -> Iterator[T]:
         return functions.catch(
             stream.upstream.accept(self),
             stream._kind,
-            stream._when,
-            stream._replacement,
+            *stream._others,
+            when=stream._when,
+            replacement=stream._replacement,
             finally_raise=stream._finally_raise,
         )
 

streamable/visitors/representation.py

@@ -35,13 +35,13 @@ def __init__(self) -> None:
     def to_string(o: object) -> str: ...
 
     def visit_catch_stream(self, stream: CatchStream[T]) -> str:
-        replacement = (
-            f", replacement={self.to_string(stream._replacement)}"
-            if stream._replacement is not NO_REPLACEMENT
-            else ""
-        )
+        replacement = ""
+        if stream._replacement is not NO_REPLACEMENT:
+            replacement = f", replacement={self.to_string(stream._replacement)}"
+
+        kinds = ', '.join(map(lambda err: getattr(err, "__name__", self.to_string(err)), (stream._kind, *stream._others)))
         self.methods_reprs.append(
-            f"catch({self.to_string(stream._kind)}, when={self.to_string(stream._when)}{replacement}, finally_raise={self.to_string(stream._finally_raise)})"
+            f"catch({kinds}, when={self.to_string(stream._when)}{replacement}, finally_raise={self.to_string(stream._finally_raise)})"
         )
         return stream.upstream.accept(self)
 
@@ -142,8 +142,5 @@ def to_string(o: object) -> str:
         if isinstance(o, _Star):
             return f"star({StrVisitor.to_string(o.func)})"
         if repr(o).startswith("<"):
-            try:
-                return getattr(o, "__name__")
-            except AttributeError:
-                return f"{o.__class__.__name__}(...)"
+            return getattr(o, "__name__", f"{o.__class__.__name__}(...)")
         return repr(o)

tests/test_stream.py

@@ -220,7 +220,8 @@ class CustomCallable:
             .flatten(concurrency=4)
             .throttle(64, interval=datetime.timedelta(seconds=1))
             .observe("foos")
-            .catch(TypeError, finally_raise=True)
+            .catch(finally_raise=True)
+            .catch(TypeError, ValueError, ZeroDivisionError)
             .catch(TypeError, replacement=None, finally_raise=True)
         )
 
@@ -279,8 +280,9 @@ class CustomCallable:
     .flatten(concurrency=4)
     .throttle(per_second=64, per_minute=inf, per_hour=inf, interval=datetime.timedelta(seconds=1))
     .observe('foos')
-    .catch(TypeError, when=bool, finally_raise=True)
-    .catch(TypeError, when=bool, replacement=None, finally_raise=True)
+    .catch(Exception, when=None, finally_raise=True)
+    .catch(TypeError, ValueError, ZeroDivisionError, when=None, finally_raise=False)
+    .catch(TypeError, when=None, replacement=None, finally_raise=True)
 )""",
             msg="`repr` should work as expected on a stream with many operation",
         )
@@ -542,7 +544,7 @@ def side_effect(x: int, func: Callable[[int], int]):
                 throw_for_odd_func_,
             ]
             for raised_exc, catched_exc in [
-                (TestError, TestError),
+                (TestError, (TestError,)),
                 (StopIteration, (WrappedError, RuntimeError)),
             ]
             for concurrency in [1, 2]
@@ -556,11 +558,11 @@ def side_effect(x: int, func: Callable[[int], int]):
     def test_map_or_foreach_with_exception(
         self,
         raised_exc: Type[Exception],
-        catched_exc: Type[Exception],
+        catched_exc: Tuple[Type[Exception], ...],
         concurrency: int,
         method: Callable[[Stream, Callable[[Any], int], int], Stream],
         throw_func: Callable[[Exception], Callable[[Any], int]],
-        throw_for_odd_func: Callable[[Exception], Callable[[Any], int]],
+        throw_for_odd_func: Callable[[Type[Exception]], Callable[[Any], int]],
     ) -> None:
         with self.assertRaises(
             catched_exc,
@@ -570,7 +572,9 @@ def test_map_or_foreach_with_exception(
 
         self.assertListEqual(
             list(
-                method(Stream(src), throw_for_odd_func(raised_exc), concurrency).catch(catched_exc)  # type: ignore
+                method(Stream(src), throw_for_odd_func(raised_exc), concurrency).catch(
+                    *catched_exc
+                )
             ),
             list(even_src),
             msg="At any concurrency, `map` and `foreach` and `amap` must not stop after one exception occured.",
@@ -1464,6 +1468,24 @@ def f(i):
             [None, 1, 0.5, 0.25],
             msg="`catch` should be able to yield a None replacement",
         )
+        self.assertListEqual(
+            list(
+                Stream(
+                    map(
+                        lambda n: 1 / n,  # potential ZeroDivisionError
+                        map(
+                            throw_for_odd_func(TestError),  # potential TestError
+                            map(
+                                int,  # potential ValueError
+                                "01234foo56789",
+                            ),
+                        ),
+                    )
+                ).catch(ValueError, TestError, ZeroDivisionError)
+            ),
+            list(map(lambda n: 1 / n, range(2, 10, 2))),
+            msg="`catch` should accept multiple types",
+        )
 
     def test_observe(self) -> None:
         value_error_rainsing_stream: Stream[List[int]] = (