From a0e75e48744b542b90bf74a6ef2a0d75aadc5c0d Mon Sep 17 00:00:00 2001
From: Iason Krommydas <iason.krom@gmail.com>
Date: Fri, 31 May 2024 15:22:22 +0200
Subject: [PATCH 1/2] add without_field, untested yet

---
 src/dask_awkward/__init__.py      |  1 +
 src/dask_awkward/lib/__init__.py  |  1 +
 src/dask_awkward/lib/structure.py | 41 +++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/src/dask_awkward/__init__.py b/src/dask_awkward/__init__.py
index 9b205092..34b5c4f5 100644
--- a/src/dask_awkward/__init__.py
+++ b/src/dask_awkward/__init__.py
@@ -100,6 +100,7 @@
     with_field,
     with_name,
     with_parameter,
+    without_field,
     without_parameters,
     zeros_like,
     zip,
diff --git a/src/dask_awkward/lib/__init__.py b/src/dask_awkward/lib/__init__.py
index 90835ff7..74d16d6c 100644
--- a/src/dask_awkward/lib/__init__.py
+++ b/src/dask_awkward/lib/__init__.py
@@ -86,6 +86,7 @@
     with_field,
     with_name,
     with_parameter,
+    without_field,
     without_parameters,
     zeros_like,
     zip,
diff --git a/src/dask_awkward/lib/structure.py b/src/dask_awkward/lib/structure.py
index ae5f104f..d7e52ed1 100644
--- a/src/dask_awkward/lib/structure.py
+++ b/src/dask_awkward/lib/structure.py
@@ -70,6 +70,7 @@
     "values_astype",
     "where",
     "with_field",
+    "without_field",
     "with_name",
     "with_parameter",
     "without_parameters",
@@ -1083,6 +1084,46 @@ def with_field(
     )
 
 
+class _WithoutFieldFn:
+    def __init__(
+        self,
+        highlevel: bool,
+        behavior: Mapping | None = None,
+        attrs: Mapping[str, Any] | None = None,
+    ) -> None:
+        self.highlevel = highlevel
+        self.behavior = behavior
+        self.attrs = attrs
+
+    def __call__(self, array: ak.Array, where: str) -> ak.Array:
+        return ak.without_field(
+            array, where=where, behavior=self.behavior, attrs=self.attrs
+        )
+
+
+@borrow_docstring(ak.without_field)
+def without_field(
+    base: Array,
+    where: str,
+    highlevel: bool = True,
+    behavior: Mapping | None = None,
+    attrs: Mapping[str, Any] | None = None,
+) -> Array:
+    if not highlevel:
+        raise ValueError("Only highlevel=True is supported")
+
+    if not isinstance(base, Array):
+        raise ValueError("Base argument in without_field must be a dask_awkward.Array")
+
+    return map_partitions(
+        _WithoutFieldFn(highlevel=highlevel, behavior=behavior, attrs=attrs),
+        base,
+        where,
+        label="without-field",
+        output_divisions=1,
+    )
+
+
 class _WithNameFn:
     def __init__(
         self,

From 3a38bf614981831ed11b3d1eb8404201318fcd46 Mon Sep 17 00:00:00 2001
From: Iason Krommydas <iason.krom@gmail.com>
Date: Fri, 31 May 2024 15:51:14 +0200
Subject: [PATCH 2/2] some testing

---
 tests/test_structure.py | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/tests/test_structure.py b/tests/test_structure.py
index d196ee35..f602e11e 100644
--- a/tests/test_structure.py
+++ b/tests/test_structure.py
@@ -212,20 +212,20 @@ def test_pad_none(axis: int, target: int) -> None:
 
 
 def test_with_field(caa: ak.Array, daa: dak.Array) -> None:
-    assert_eq(
-        ak.with_field(caa["points"], caa["points"]["x"], where="xx"),
-        dak.with_field(daa["points"], daa["points"]["x"], where="xx"),
-    )
+    new_caa = ak.with_field(caa["points"], caa["points"]["x"], where="xx")
+    new_daa = dak.with_field(daa["points"], daa["points"]["x"], where="xx")
+    assert_eq(new_caa, new_daa)
+    assert_eq(ak.without_field(new_caa, "xx"), ak.without_field(new_daa, "xx"))
 
-    assert_eq(
-        ak.with_field(caa["points"], 1, where="xx"),
-        dak.with_field(daa["points"], 1, where="xx"),
-    )
+    new_caa = ak.with_field(caa["points"], 1, where="xx")
+    new_daa = dak.with_field(daa["points"], 1, where="xx")
+    assert_eq(new_caa, new_daa)
+    assert_eq(ak.without_field(new_caa, "xx"), ak.without_field(new_daa, "xx"))
 
-    assert_eq(
-        ak.with_field(caa["points"], 1.0, where="xx"),
-        dak.with_field(daa["points"], 1.0, where="xx"),
-    )
+    new_caa = ak.with_field(caa["points"], 1.0, where="xx")
+    new_daa = dak.with_field(daa["points"], 1.0, where="xx")
+    assert_eq(new_caa, new_daa)
+    assert_eq(ak.without_field(new_caa, "xx"), ak.without_field(new_daa, "xx"))
 
     with pytest.raises(
         ValueError,
@@ -233,6 +233,15 @@ def test_with_field(caa: ak.Array, daa: dak.Array) -> None:
     ):
         _ = dak.with_field([{"foo": 1.0}, {"foo": 2.0}], daa.points.x, where="x")
 
+    with pytest.raises(
+        ValueError,
+        match="Base argument in without_field must be a dask_awkward.Array",
+    ):
+        _ = dak.without_field(
+            [{"foo": [1.0, 2.0], "bar": [3.0, 4.0]}],
+            "bar",
+        )
+
     with pytest.raises(
         ValueError,
         match="with_field cannot accept string, bytes, list, or dict values yet",