Add maybe_apply function (#223)

* Add `maybe_apply` function * Add apply functions * Add typing tests * Rename excs as exceptions * Default value is the object, use UNSET * Default not fallback * Rename apply_catch * Fix pytest version --------- Co-authored-by: DeviousStoat <[email protected]>
dgilland · Mar 4, 2024 · 81b4a99 · 81b4a99
1 parent 079ab36
commit 81b4a99
Show file tree

Hide file tree

Showing 10 changed files with 213 additions and 42 deletions.
diff --git a/pyproject.toml b/pyproject.toml
@@ -44,7 +44,8 @@ dev = [
   "furo",
   "invoke",
   "mypy",
-  "pytest",
+  # pytest 8+ is not supported by pytest-mypy-testing
+  "pytest <8",
   "pytest-mypy-testing",
   "pytest-cov",
   "sphinx",

diff --git a/src/pydash/__init__.py b/src/pydash/__init__.py
@@ -79,7 +79,7 @@
     zip_object_deep,
     zip_with,
 )
-from .chaining import _Dash, chain, tap, thru
+from .chaining import _Dash, chain, tap
 from .collections import (
     at,
     count_by,
@@ -168,6 +168,10 @@
     zscore,
 )
 from .objects import (
+    apply,
+    apply_catch,
+    apply_if,
+    apply_if_not_none,
     assign,
     assign_with,
     callables,
@@ -462,7 +466,6 @@
     "_Dash",
     "chain",
     "tap",
-    "thru",
     "at",
     "count_by",
     "every",
@@ -544,6 +547,10 @@
     "transpose",
     "variance",
     "zscore",
+    "apply",
+    "apply_catch",
+    "apply_if",
+    "apply_if_not_none",
     "assign",
     "assign_with",
     "callables",

diff --git a/src/pydash/chaining/__init__.py b/src/pydash/chaining/__init__.py
@@ -1,9 +1,8 @@
-from .chaining import _Dash, chain, tap, thru
+from .chaining import _Dash, chain, tap
 
 
 __all__ = (
     "_Dash",
     "chain",
     "tap",
-    "thru",
 )
diff --git a/src/pydash/chaining/all_funcs.pyi b/src/pydash/chaining/all_funcs.pyi
@@ -700,9 +700,6 @@ class AllFuncs:
     def tap(self: "Chain[T]", interceptor: t.Callable[[T], t.Any]) -> "Chain[T]":
         return self._wrap(pyd.tap)(interceptor)
 
-    def thru(self: "Chain[T]", interceptor: t.Callable[[T], T2]) -> "Chain[T2]":
-        return self._wrap(pyd.thru)(interceptor)
-
     @t.overload
     def at(self: "Chain[t.Mapping[T, T2]]", *paths: T) -> "Chain[t.List[t.Union[T2, None]]]": ...
     @t.overload
@@ -2578,6 +2575,36 @@ class AllFuncs:
     ) -> "Chain[t.Any]":
         return self._wrap(pyd.map_values_deep)(iteratee, property_path)
 
+    def apply(self: "Chain[T]", func: t.Callable[[T], T2]) -> "Chain[T2]":
+        return self._wrap(pyd.apply)(func)
+
+    def apply_if(
+        self: "Chain[T]", func: t.Callable[[T], T2], predicate: t.Callable[[T], bool]
+    ) -> "Chain[t.Union[T, T2]]":
+        return self._wrap(pyd.apply_if)(func, predicate)
+
+    def apply_if_not_none(
+        self: "Chain[t.Optional[T]]", func: t.Callable[[T], T2]
+    ) -> "Chain[t.Optional[T2]]":
+        return self._wrap(pyd.apply_if_not_none)(func)
+
+    @t.overload
+    def apply_catch(
+        self: "Chain[T]",
+        func: t.Callable[[T], T2],
+        exceptions: t.Iterable[t.Type[Exception]],
+        default: T3,
+    ) -> "Chain[t.Union[T2, T3]]": ...
+    @t.overload
+    def apply_catch(
+        self: "Chain[T]",
+        func: t.Callable[[T], T2],
+        exceptions: t.Iterable[t.Type[Exception]],
+        default: Unset = UNSET,
+    ) -> "Chain[t.Union[T, T2]]": ...
+    def apply_catch(self, func, exceptions, default=UNSET):
+        return self._wrap(pyd.apply_catch)(func, exceptions, default)
+
     @t.overload
     def merge(
         self: "Chain[t.Mapping[T, T2]]", *sources: t.Mapping[T3, T4]

diff --git a/src/pydash/chaining/chaining.py b/src/pydash/chaining/chaining.py
@@ -16,7 +16,6 @@
 __all__ = (
     "chain",
     "tap",
-    "thru",
 )
 
 ValueT_co = t.TypeVar("ValueT_co", covariant=True)
@@ -263,25 +262,3 @@ def tap(value: T, interceptor: t.Callable[[T], t.Any]) -> T:
     """
     interceptor(value)
     return value
-
-
-def thru(value: T, interceptor: t.Callable[[T], T2]) -> T2:
-    """
-    Returns the result of calling `interceptor` on `value`. The purpose of this method is to pass
-    `value` through a function during a method chain.
-
-    Args:
-        value: Current value of chain operation.
-        interceptor: Function called with `value`.
-
-    Returns:
-        Results of ``interceptor(value)``.
-
-    Example:
-
-        >>> chain([1, 2, 3, 4]).thru(lambda x: x * 2).value()
-        [1, 2, 3, 4, 1, 2, 3, 4]
-
-    .. versionadded:: 2.0.0
-    """
-    return interceptor(value)
diff --git a/src/pydash/objects.py b/src/pydash/objects.py
@@ -12,7 +12,7 @@
 
 import pydash as pyd
 
-from .helpers import UNSET, base_get, base_set, callit, getargcount, iterator, iteriteratee
+from .helpers import UNSET, Unset, base_get, base_set, callit, getargcount, iterator, iteriteratee
 from .types import IterateeObjT, PathT
 from .utilities import PathToken, to_path, to_path_tokens
 
@@ -21,6 +21,10 @@
     from _typeshed import SupportsRichComparisonT  # pragma: no cover
 
 __all__ = (
+    "apply",
+    "apply_catch",
+    "apply_if",
+    "apply_if_not_none",
     "assign",
     "assign_with",
     "callables",
@@ -1251,6 +1255,121 @@ def deep_iteratee(value, key):
         return callit(iteratee, obj, properties)
 
 
+def apply(obj: T, func: t.Callable[[T], T2]) -> T2:
+    """
+    Returns the result of calling `func` on `obj`. Particularly useful to pass
+    `obj` through a function during a method chain.
+
+    Args:
+        obj: Object to apply function to
+        func: Function called with `obj`.
+
+    Returns:
+        Results of ``func(value)``.
+
+    Example:
+
+        >>> apply(5, lambda x: x * 2)
+        10
+
+    .. versionadded:: 8.0.0
+    """
+    return func(obj)
+
+
+def apply_if(obj: T, func: t.Callable[[T], T2], predicate: t.Callable[[T], bool]) -> t.Union[T, T2]:
+    """
+    Apply `func` to `obj` if `predicate` returns `True`.
+
+    Args:
+        obj: Object to apply `func` to.
+        func: Function to apply to `obj`.
+        predicate: Predicate applied to `obj`.
+
+    Returns:
+        Result of applying `func` to `obj` or `obj`.
+
+    Example:
+
+        >>> apply_if(2, lambda x: x * 2, lambda x: x > 1)
+        4
+        >>> apply_if(2, lambda x: x * 2, lambda x: x < 1)
+        2
+
+    .. versionadded:: 8.0.0
+    """
+    return func(obj) if predicate(obj) else obj
+
+
+def apply_if_not_none(obj: t.Optional[T], func: t.Callable[[T], T2]) -> t.Optional[T2]:
+    """
+    Apply `func` to `obj` if `obj` is not ``None``.
+
+    Args:
+        obj: Object to apply `func` to.
+        func: Function to apply to `obj`.
+
+    Returns:
+        Result of applying `func` to `obj` or ``None``.
+
+    Example:
+
+        >>> apply_if_not_none(2, lambda x: x * 2)
+        4
+        >>> apply_if_not_none(None, lambda x: x * 2) is None
+        True
+
+    .. versionadded:: 8.0.0
+    """
+    return apply_if(obj, func, lambda x: x is not None)  # type: ignore
+
+
+@t.overload
+def apply_catch(
+    obj: T, func: t.Callable[[T], T2], exceptions: t.Iterable[t.Type[Exception]], default: T3
+) -> t.Union[T2, T3]: ...
+
+
+@t.overload
+def apply_catch(
+    obj: T,
+    func: t.Callable[[T], T2],
+    exceptions: t.Iterable[t.Type[Exception]],
+    default: Unset = UNSET,
+) -> t.Union[T, T2]: ...
+
+
+def apply_catch(obj, func, exceptions, default=UNSET):
+    """
+    Tries to apply `func` to `obj` if any of the exceptions in `excs` are raised, return `default`
+    or `obj` if not set.
+
+    Args:
+        obj: Object to apply `func` to.
+        func: Function to apply to `obj`.
+        excs: Exceptions to catch.
+        default: Value to return if exception is raised.
+
+    Returns:
+        Result of applying `func` to `obj` or ``default``.
+
+    Example:
+
+        >>> apply_catch(2, lambda x: x * 2, [ValueError])
+        4
+        >>> apply_catch(2, lambda x: x / 0, [ZeroDivisionError], "error")
+        'error'
+        >>> apply_catch(2, lambda x: x / 0, [ZeroDivisionError])
+        2
+
+    .. versionadded:: 8.0.0
+    """
+    try:
+        return func(obj)
+    except tuple(exceptions):
+        return obj if default is UNSET else default
+
+
 @t.overload
 def merge(
     obj: t.Mapping[T, T2], *sources: t.Mapping[T3, T4]

diff --git a/tests/pytest_mypy_testing/test_chaining.py b/tests/pytest_mypy_testing/test_chaining.py
@@ -35,8 +35,3 @@ def log(value):
         data.append(value)
 
     reveal_type(_.chain([1, 2, 3, 4]).map(lambda x: x * 2).tap(log).value())  # R: builtins.list[builtins.int]
-
-
-@pytest.mark.mypy_testing
-def test_mypy_thru() -> None:
-    reveal_type(_.chain([1, 2, 3, 4]).thru(lambda x: x * 2).value())  # R: builtins.list[builtins.int]
diff --git a/tests/pytest_mypy_testing/test_objects.py b/tests/pytest_mypy_testing/test_objects.py
@@ -345,3 +345,28 @@ def test_mypy_values() -> None:
     reveal_type(_.values({'a': 1, 'b': 2, 'c': 3}))  # R: builtins.list[builtins.int]
     reveal_type(_.values([2, 4, 6, 8]))  # R: builtins.list[builtins.int]
     reveal_type(_.values(MyClass()))  # R: builtins.list[Any]
+
+
+@pytest.mark.mypy_testing
+def test_mypy_apply() -> None:
+    reveal_type(_.apply("1", lambda x: int(x)))  # R: builtins.int
+    reveal_type(_.apply(1, lambda x: x + 1))  # R: builtins.int
+    reveal_type(_.apply("hello", lambda x: x.upper()))  # R: builtins.str
+
+
+@pytest.mark.mypy_testing
+def test_mypy_apply_if() -> None:
+    reveal_type(_.apply_if("5", lambda x: int(x), lambda x: x.isdecimal()))  # R: Union[builtins.str, builtins.int]
+
+
+@pytest.mark.mypy_testing
+def test_mypy_apply_if_not_none() -> None:
+    reveal_type(_.apply_if_not_none(1, lambda x: x + 1))  # R: Union[builtins.int, None]
+    reveal_type(_.apply_if_not_none(None, lambda x: x + 1))  # R: Union[builtins.int, None]
+    reveal_type(_.apply_if_not_none("hello", lambda x: x.upper()))  # R: Union[builtins.str, None]
+
+
+@pytest.mark.mypy_testing
+def test_mypy_apply_catch() -> None:
+    reveal_type(_.apply_catch(5, lambda x: x / 0, [ZeroDivisionError]))  # R: Union[builtins.int, builtins.float]
+    reveal_type(_.apply_catch(5, lambda x: x / 0, [ZeroDivisionError], "error"))  # R: Union[builtins.float, builtins.str]
diff --git a/tests/test_chaining.py b/tests/test_chaining.py
@@ -165,8 +165,3 @@ def test_chaining_value_to_string(case, expected):
 def test_tap(value, interceptor, expected):
     actual = _.chain(value).initial().tap(interceptor).last().value()
     assert actual == expected
-
-
-@parametrize("value,func,expected", [([1, 2, 3, 4, 5], lambda value: [sum(value)], 10)])
-def test_thru(value, func, expected):
-    assert _.chain(value).initial().thru(func).last().value()
diff --git a/tests/test_objects.py b/tests/test_objects.py
@@ -944,3 +944,29 @@ def test_unset(obj, path, expected, new_obj):
 @parametrize("case,expected", [({"a": 1, "b": 2, "c": 3}, [1, 2, 3]), ([1, 2, 3], [1, 2, 3])])
 def test_values(case, expected):
     assert set(_.values(case)) == set(expected)
+
+
+@parametrize("case,expected", [((5, lambda x: x * 2), 10)])
+def test_apply(case, expected):
+    assert _.apply(*case) == expected
+
+
+@parametrize(
+    "case,expected",
+    [((5, lambda x: x * 2, lambda x: x == 5), 10), ((5, lambda x: x * 2, lambda x: x == 10), 5)],
+)
+def test_apply_if(case, expected):
+    assert _.apply_if(*case) == expected
+
+
+@parametrize("case,expected", [((5, lambda x: x * 2), 10), ((None, lambda x: x * 2), None)])
+def test_apply_if_not_none(case, expected):
+    assert _.apply_if_not_none(*case) == expected
+
+
+@parametrize(
+    "case,expected",
+    [((5, lambda x: x * 2, [ValueError]), 10), ((5, lambda x: x / 0, [ZeroDivisionError]), 5)],
+)
+def test_apply_catch(case, expected):
+    assert _.apply_catch(*case) == expected