From e68d5c3867a27199f3f6845a0a7fc52c89aa02d6 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 11 Oct 2026 00:26:59 +0000
Subject: [PATCH 1/2] Initial plan


From 34e2e0e7c66e077eb0e4197133d11040cd329d8d Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 11 Oct 2026 00:31:39 +0000
Subject: [PATCH 2/2] Apply remaining changes

Co-authored-by: ebhills <53243273+ebhills@users.noreply.github.com>
---
 tests/recipes/test_write.py | 20 ++++++++++++++++++++
 wrangles/recipe.py          | 35 ++++++++++++++++++++++++++++++-----
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/tests/recipes/test_write.py b/tests/recipes/test_write.py
index 0dd507e37..3671887eb 100644
--- a/tests/recipes/test_write.py
+++ b/tests/recipes/test_write.py
@@ -110,6 +110,26 @@ def test_specify_not_columns_regex():
     df = wrangles.recipe.run(recipe, dataframe=data)
     assert df.columns == ['3col']
 
+
+def test_specify_not_columns_missing_ignored():
+    """
+    Test writing and excluding a subset of columns while ignoring names that don't exist
+    """
+    data = pd.DataFrame({
+        'col1': ['val1'],
+        'col2': ['val2']
+    })
+    recipe = """
+    write:
+      - dataframe:
+          not_columns:
+            - missing_col
+            - col2
+    """
+    df = wrangles.recipe.run(recipe, dataframe=data)
+    assert df.columns.tolist() == ['col1']
+
+
 def test_specify_where():
     """
     Test writing and applying a WHERE sql criteria
diff --git a/wrangles/recipe.py b/wrangles/recipe.py
index bea3cdb8c..17c21f4d2 100644
--- a/wrangles/recipe.py
+++ b/wrangles/recipe.py
@@ -1104,12 +1104,37 @@ def _filter_dataframe(
         columns = _wildcard_expansion(df.columns.tolist(), columns)
         df = df[columns]
 
-    # Remove any columns specified by the user
+    # Remove any columns specified by the user. Missing names are ignored so
+    # not_columns behaves like a no-op for absent fields instead of raising.
     if not_columns:
-        not_columns = _wildcard_expansion(df.columns.tolist(), not_columns)
-        # List comprehension is used below to preserve order of columns 
-        remaining_columns = [column for column in list(df.columns) if column not in not_columns]
-        df = df[remaining_columns]
+        if isinstance(not_columns, (str, int)):
+            not_columns = [not_columns]
+        else:
+            not_columns = list(not_columns)
+
+        valid_not_columns = []
+        for column in not_columns:
+            if column is None:
+                continue
+
+            # Negative selectors are valid even when they don't match any current
+            # columns, because they are meant to remove matching columns if present.
+            if isinstance(column, str) and column.startswith('-'):
+                valid_not_columns.append(column)
+                continue
+
+            try:
+                _wildcard_expansion(df.columns.tolist(), [column])
+            except KeyError:
+                continue
+
+            valid_not_columns.append(column)
+
+        if valid_not_columns:
+            not_columns = _wildcard_expansion(df.columns.tolist(), valid_not_columns)
+            # List comprehension is used below to preserve order of columns
+            remaining_columns = [column for column in list(df.columns) if column not in not_columns]
+            df = df[remaining_columns]
 
     return df