modernize type hints

clj/seqs.py

@@ -3,7 +3,7 @@
 import collections.abc as collections_abc
 import itertools
 import random
-from typing import Iterable, TypeVar, Any, Callable, Iterator, Union, Tuple, Dict, Optional, List, Set, cast, Deque
+from typing import Iterable, TypeVar, Any, Callable, Iterator, Union, cast, Deque
 
 import clj
 
@@ -224,7 +224,7 @@ def butlast(coll: Iterable[T]) -> Iterable[T]:
     Return a generator of all but the last item in ``coll``, in linear time.
     """
     first_ = True
-    last_e: Optional[T] = None
+    last_e: T | None = None
     for e in coll:
         if first_:
             last_e = e
@@ -303,7 +303,7 @@ def _iter(coll, n=0):
     return coll[n:]
 
 
-def split_at(n: int, coll: Iterable[T]) -> Tuple[Iterable[T], Iterable[T]]:
+def split_at(n: int, coll: Iterable[T]) -> tuple[Iterable[T], Iterable[T]]:
     """
     Returns a tuple of ``(take(n, coll), drop(n coll))``.
     """
@@ -325,7 +325,7 @@ def split_at(n: int, coll: Iterable[T]) -> Tuple[Iterable[T], Iterable[T]]:
     return taken, _iter(coll, n)
 
 
-def split_with(pred: Callable[[T], Any], coll: Iterable[T]) -> Tuple[Iterable[T], Iterable[T]]:
+def split_with(pred: Callable[[T], Any], coll: Iterable[T]) -> tuple[Iterable[T], Iterable[T]]:
     """
     Returns a tuple of ``(take_while(pred, coll), drop_while(pred coll))``.
     """
@@ -348,7 +348,7 @@ def dropped_while():
     return taken, dropped_while()
 
 
-def replace(smap: Dict[T, T2], coll: Iterable[T]) -> Iterable[Union[T, T2]]:
+def replace(smap: dict[T, T2], coll: Iterable[T]) -> Iterable[Union[T, T2]]:
     """
     Given a map of replacement pairs and a list/collection, yield a sequence
     where any element = a key in ``smap`` replaced with the corresponding val
@@ -396,7 +396,7 @@ def map_indexed(f: Callable[[int, T], T2], coll: Iterable[T]) -> Iterable[T2]:
     return map(lambda pair: f(pair[0], pair[1]), enumerate(coll))
 
 
-def _first(coll: Iterable[T]) -> Tuple[Optional[T], bool]:
+def _first(coll: Iterable[T]) -> tuple[T | None, bool]:
     """
     Like first(coll), but return a tuple of ``(first, is_empty)`` where `first` is either the first
     element of the collection or ``None`` and ``is_empty`` is a boolean that is ``True`` if the collection
@@ -409,18 +409,18 @@ def _first(coll: Iterable[T]) -> Tuple[Optional[T], bool]:
     first_value: Union[T, object] = next(_make_gen(take(1, coll)), _flag)
     if first_value is _flag:
         return None, True
-    return cast(Optional[T], first_value), False
+    return cast(T | None, first_value), False
 
 
-def first(coll: Iterable[T]) -> Optional[T]:
+def first(coll: Iterable[T]) -> T | None:
     """
     Returns the first item in the collection. If ``coll`` is empty, returns ``None``.
     """
-    first_value: Optional[T] = _first(coll)[0]
+    first_value: T | None = _first(coll)[0]
     return first_value
 
 
-def ffirst(x: Iterable[Iterable[T]]) -> Optional[T]:
+def ffirst(x: Iterable[Iterable[T]]) -> T | None:
     """
     Same as ``first(first(x))``
     """
@@ -440,7 +440,7 @@ def nfirst(x: Iterable[Iterable[T]]) -> Iterable[T]:
     return rest(f)
 
 
-def second(coll: Iterable[T]) -> Optional[T]:
+def second(coll: Iterable[T]) -> T | None:
     """
     Same as ``first(rest(coll))``.
     """
@@ -473,7 +473,7 @@ def nth(coll: Iterable[T], n: int, not_found: Any = _nil) -> Any:
     return not_found
 
 
-def last(coll: Iterable[T]) -> Optional[T]:
+def last(coll: Iterable[T]) -> T | None:
     """
     Return the last item in ``coll``, in linear time. Return ``None`` if ``coll`` is empty.
     """
@@ -483,14 +483,14 @@ def last(coll: Iterable[T]) -> Optional[T]:
     return e
 
 
-def zipmap(keys: Iterable[T], vals: Iterable[T2]) -> Dict[T, T2]:
+def zipmap(keys: Iterable[T], vals: Iterable[T2]) -> dict[T, T2]:
     """
     Return a ``dict`` with the keys mapped to the corresponding ``vals``.
     """
     return dict(zip(keys, vals))
 
 
-def group_by(f: Callable[[T], T2], coll: Iterable[T]) -> Dict[T2, List[T]]:
+def group_by(f: Callable[[T], T2], coll: Iterable[T]) -> dict[T2, list[T]]:
     """
     Returns a ``dict`` of the elements of ``coll`` keyed by the result of ``f``
     on each element. The value at each key will be a list of the corresponding
@@ -503,14 +503,14 @@ def group_by(f: Callable[[T], T2], coll: Iterable[T]) -> Dict[T2, List[T]]:
     return dict(groups)
 
 
-def _make_pred(pred: Union[Callable[[T], T2], Set[T]]) -> Callable[[T], Union[T2, bool]]:
+def _make_pred(pred: Union[Callable[[T], T2], set[T]]) -> Callable[[T], Union[T2, bool]]:
     if isinstance(pred, set):
-        return lambda x: x in cast(Set[T], pred)
+        return lambda x: x in cast(set[T], pred)
 
     return pred
 
 
-def some(pred: Union[Callable[[T], Any], Set[T]], coll: Iterable[T]) -> Optional[T]:
+def some(pred: Union[Callable[[T], Any], set[T]], coll: Iterable[T]) -> T | None:
     """
     Returns the first logical true value of ``pred(x)`` for any ``x`` in coll,
     else ``None``.
@@ -536,7 +536,7 @@ def is_seq(x):
     return isinstance(x, collections_abc.Sequence)
 
 
-def every(pred: Union[Callable[[T], Any], Set[T]], coll: Iterable[T]) -> bool:
+def every(pred: Union[Callable[[T], Any], set[T]], coll: Iterable[T]) -> bool:
     """
     Returns ``True`` if ``pred(x)`` is logical true for every ``x`` in
     ``coll``, else i``False``.
@@ -550,15 +550,15 @@ def every(pred: Union[Callable[[T], Any], Set[T]], coll: Iterable[T]) -> bool:
     return True
 
 
-def not_every(pred: Union[Callable[[T], Any], Set[T]], coll: Iterable[T]) -> bool:
+def not_every(pred: Union[Callable[[T], Any], set[T]], coll: Iterable[T]) -> bool:
     """
     Returns ``False`` if ``pred(x)`` is logical true for every ``x`` in
     ``coll``, else ``True``.
     """
     return not every(pred, coll)
 
 
-def not_any(pred: Union[Callable[[T], Any], Set[T]], coll: Iterable[T]) -> bool:
+def not_any(pred: Union[Callable[[T], Any], set[T]], coll: Iterable[T]) -> bool:
     """
     Return ``False`` if ``pred(x)`` is logical true for any ``x`` in ``coll``,
     else ``True``.
@@ -581,7 +581,7 @@ def dorun(coll: Iterable) -> None:
     return None
 
 
-def repeatedly(f: Union[Callable[[], T2], int], n: Optional[Union[int, Callable[[], T2]]] = None) \
+def repeatedly(f: Union[Callable[[], T2], int], n: Union[int, Callable[[], T2]] | None = None) \
         -> Iterable[T2]:
     """
     Takes a function of no args, presumably with side effects, and returns an
@@ -611,7 +611,7 @@ def iterate(f: Callable[[Any], Any], x) -> Iterable:
         x = f(x)
 
 
-def repeat(x: T, n: Optional[int] = None) -> Iterable[T]:
+def repeat(x: T, n: int | None = None) -> Iterable[T]:
     """
     Returns a generator that indefinitely yields ``x`` (or ``n`` times if ``n`` is supplied).
 
@@ -688,7 +688,7 @@ def dedupe(coll: Iterable[T]) -> Iterable[T]:
         prev = e
 
 
-def empty(coll: T) -> Optional[T]:
+def empty(coll: T) -> T | None:
     """
     Returns an empty collection of the same type as ``coll``, or ``None``.
     """
@@ -713,8 +713,8 @@ def count(coll: Iterable) -> int:
     return n
 
 
-def partition(coll: Iterable[T], n: int, step: Optional[int] = None, pad: Optional[Iterable[T2]] = None) \
-        -> Iterator[List[Union[T, T2]]]:
+def partition(coll: Iterable[T], n: int, step: int | None = None, pad: Iterable[T2] | None = None) \
+        -> Iterator[list[Union[T, T2]]]:
     """
     Returns a generator of lists of ``n`` items each, at offsets ``step`` apart. If ``step`` is not supplied, defaults
     to ``n``, i.e. the partitions do not overlap. If a ``pad`` collection is supplied, use its elements as necessary to
@@ -733,7 +733,7 @@ def partition(coll: Iterable[T], n: int, step: Optional[int] = None, pad: Option
         # TODO
         raise NotImplementedError("Step != n is not supported for now.")
 
-    current_partition: List[Union[T, T2]] = []
+    current_partition: list[Union[T, T2]] = []
     partition_index = 0
     partition_end = n
 
@@ -755,8 +755,8 @@ def partition(coll: Iterable[T], n: int, step: Optional[int] = None, pad: Option
         yield current_partition
 
 
-def partition_by(f: Callable[[T], Any], coll: Iterable[T]) -> Iterable[List[T]]:
-    current: List[T] = []
+def partition_by(f: Callable[[T], Any], coll: Iterable[T]) -> Iterable[list[T]]:
+    current: list[T] = []
     current_value = None
     for element in coll:
         if not current:
@@ -777,7 +777,7 @@ def partition_by(f: Callable[[T], Any], coll: Iterable[T]) -> Iterable[List[T]]:
         yield current
 
 
-def seq_gen(coll: Iterable[T]) -> Optional[Iterable[T]]:
+def seq_gen(coll: Iterable[T]) -> Iterable[T] | None:
     """
     Like Clojure’s ``seq``, but return a lazy iterable that’s equivalent to ``coll`` if not empty.
 
@@ -789,5 +789,5 @@ def seq_gen(coll: Iterable[T]) -> Optional[Iterable[T]]:
     """
     first_element, _is_empty = _first(coll)
     if _is_empty:
-        return
+        return None
     return clj.concat([first_element], _iter(coll, 1))

tests/test_seqs.py

@@ -246,7 +246,7 @@ def test_flatten_infinite_generators():
 
 
 def test_flatten_deep_list():
-    deep_list = ["foo"]
+    deep_list: list[Any] = ["foo"]
     for _ in range(200):
         deep_list = [[[[[deep_list]]]]]