diff --git a/databooks/affirm.py b/databooks/affirm.py
index d317d433..726c0712 100644
--- a/databooks/affirm.py
+++ b/databooks/affirm.py
@@ -1,7 +1,7 @@
 """Functions to safely evaluate strings and inspect notebook."""
 import ast
+from collections import abc
 from copy import deepcopy
-from functools import reduce
 from itertools import compress
 from pathlib import Path
 from typing import Any, Callable, Dict, Iterable, List, Tuple
@@ -99,6 +99,26 @@ def _prioritize(field: Tuple[str, Any]) -> bool:
             return True
         return not any(isinstance(f, ast.comprehension) for f in value)
 
+    @staticmethod
+    def _allowed_attr(obj: Any, attr: str, is_dynamic: bool = False) -> None:
+        """
+        Check that attribute is a key of `databooks.data_models.base.DatabooksBase`.
+
+        If `obj` is an iterable and was computed dynamically (that is, not originally in
+         scope but computed from a comprehension), check attributes for all elements in
+         the iterable.
+        """
+        allowed_attrs = list(dict(obj).keys()) if isinstance(obj, DatabooksBase) else ()
+        if isinstance(obj, abc.Iterable) and is_dynamic:
+            for el in obj:
+                DatabooksParser._allowed_attr(obj=el, attr=attr)
+        else:
+            if attr not in allowed_attrs:
+                raise ValueError(
+                    "Expected attribute to be one of"
+                    f" `{allowed_attrs}`, got `{attr}` for {obj}."
+                )
+
     def _get_iter(self, node: ast.AST) -> Iterable:
         """Use `DatabooksParser.safe_eval_ast` to get the iterable object."""
         tree = ast.Expression(body=node)
@@ -131,13 +151,7 @@ def visit_comprehension(self, node: ast.comprehension) -> None:
                 "Expected `ast.comprehension`'s target to be `ast.Name`, got"
                 f" `ast.{type(node.target).__name__}`."
             )
-        # If any elements in the comprehension are a `DatabooksBase` instance, then
-        #  pass down the attributes as valid
-        iterable = self._get_iter(node.iter)
-        databooks_el = [el for el in iterable if isinstance(el, DatabooksBase)]
-        if databooks_el:
-            d_attrs = reduce(lambda a, b: {**a, **b}, [dict(el) for el in databooks_el])
-        self.names[node.target.id] = DatabooksBase(**d_attrs) if databooks_el else ...
+        self.names[node.target.id] = self._get_iter(node.iter)
         self.generic_visit(node)
 
     def visit_Attribute(self, node: ast.Attribute) -> None:
@@ -148,13 +162,11 @@ def visit_Attribute(self, node: ast.Attribute) -> None:
                 f" `ast.Subscript`, got `ast.{type(node.value).__name__}`."
             )
         if isinstance(node.value, ast.Name):
-            obj = self.names[node.value.id]
-            allowed_attrs = dict(obj).keys() if isinstance(obj, DatabooksBase) else ()
-            if node.attr not in allowed_attrs:
-                raise ValueError(
-                    "Expected attribute to be one of"
-                    f" `{allowed_attrs}`, got `{node.attr}`"
-                )
+            self._allowed_attr(
+                obj=self.names[node.value.id],
+                attr=node.attr,
+                is_dynamic=node.value.id in (self.names.keys() - self.scope.keys()),
+            )
         self.generic_visit(node)
 
     def visit_Name(self, node: ast.Name) -> None:
diff --git a/tests/files/clean.ipynb b/tests/files/clean.ipynb
new file mode 100644
index 00000000..1d8c57dc
--- /dev/null
+++ b/tests/files/clean.ipynb
@@ -0,0 +1,113 @@
+{
+  "nbformat": 4,
+  "nbformat_minor": 5,
+  "metadata": {},
+  "cells": [
+    {
+      "metadata": {},
+      "source": [
+        "# `databooks` demo!"
+      ],
+      "cell_type": "markdown"
+    },
+    {
+      "metadata": {},
+      "source": [
+        "random()"
+      ],
+      "cell_type": "code",
+      "outputs": [
+        {
+          "data": {
+            "text/plain": [
+              "0.8025984025011855"
+            ]
+          },
+          "execution_count": 2,
+          "metadata": {},
+          "output_type": "execute_result"
+        }
+      ],
+      "execution_count": null
+    },
+    {
+      "metadata": {},
+      "source": [
+        "from random import random"
+      ],
+      "cell_type": "code",
+      "outputs": [],
+      "execution_count": null
+    },
+    {
+      "metadata": {},
+      "source": [
+        "print(\"It helps with resolving git conflicts but also avoiding them in the first place! \ud83c\udf89\")"
+      ],
+      "cell_type": "code",
+      "outputs": [
+        {
+          "name": "stdout",
+          "output_type": "stream",
+          "text": [
+            "It helps with resolving git conflicts but also avoiding them in the first place! \ud83c\udf89\n"
+          ]
+        }
+      ],
+      "execution_count": null
+    },
+    {
+      "metadata": {},
+      "source": [
+        "vals = range(1,4)"
+      ],
+      "cell_type": "code",
+      "outputs": [],
+      "execution_count": null
+    },
+    {
+      "metadata": {},
+      "source": [
+        "for v in vals:\n",
+        "    print(v)"
+      ],
+      "cell_type": "code",
+      "outputs": [
+        {
+          "name": "stdout",
+          "output_type": "stream",
+          "text": [
+            "1\n",
+            "2\n",
+            "3\n"
+          ]
+        }
+      ],
+      "execution_count": null
+    },
+    {
+      "metadata": {},
+      "source": [
+        "print(\"As easy as running `databooks fix .`\")"
+      ],
+      "cell_type": "code",
+      "outputs": [
+        {
+          "name": "stdout",
+          "output_type": "stream",
+          "text": [
+            "As easy as running `databooks fix .`\n"
+          ]
+        }
+      ],
+      "execution_count": null
+    },
+    {
+      "metadata": {},
+      "source": [],
+      "cell_type": "code",
+      "outputs": [],
+      "execution_count": null
+    }
+  ]
+}
diff --git a/tests/test_affirm.py b/tests/test_affirm.py
index 0b4eabe7..621707a2 100644
--- a/tests/test_affirm.py
+++ b/tests/test_affirm.py
@@ -41,6 +41,12 @@ def test_comprehension(self) -> None:
         parser = DatabooksParser(n=[1, 2, 3])
         assert parser.safe_eval("[i+1 for i in n]") == [2, 3, 4]
 
+    def test_nested_comprehension(self) -> None:
+        """Variables in nested iterables should be valid."""
+        parser = DatabooksParser(m=[1, 2], n=[3, 4], o={1: 10, -1: -10})
+        res_eval = parser.safe_eval("[(i+j)*k for j in m for i in n for k in o]")
+        assert res_eval == [4, -4, 5, -5, 5, -5, 6, -6]
+
     def test_multiply(self) -> None:
         """Multiplications are valid."""
         parser = DatabooksParser()
@@ -79,6 +85,21 @@ def test_nested_attributes(self) -> None:
         parser = DatabooksParser(model=DatabooksBase(a=DatabooksBase(b=2)))
         assert parser.safe_eval("model.a.b") == 2
 
+    def test_nested_attributes_comprehensions(self) -> None:
+        """Nested attributes from Pydantic fields in nested comprehensions are valid."""
+        parser = DatabooksParser(
+            l1=[
+                DatabooksBase(a=DatabooksBase(b=1)),
+                DatabooksBase(a=DatabooksBase(b=2)),
+            ],
+            l2=[
+                DatabooksBase(a=DatabooksBase(b=3)),
+                DatabooksBase(a=DatabooksBase(b=4)),
+            ],
+        )
+        res_eval = parser.safe_eval("[m1.a.b+m2.a.b for m1 in l1 for m2 in l2]")
+        assert res_eval == [4, 5, 5, 6]
+
     def test_eval(self) -> None:
         """Trying accessing built-in `eval` raises error."""
         parser = DatabooksParser()
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 6f9a0ac2..41b0282b 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -214,10 +214,10 @@ def test_assert__config(caplog: LogCaptureFixture) -> None:
         )
     logs = list(caplog.records)
     assert result.exit_code == 1
-    assert len(logs) == 3
+    assert len(logs) == 4
     assert (
         logs[-1].message
-        == "Found issues in notebook metadata for 1 out of 2 notebooks."
+        == "Found issues in notebook metadata for 2 out of 3 notebooks."
     )
 
 
diff --git a/tests/test_recipes.py b/tests/test_recipes.py
index cf2740eb..e0765a29 100644
--- a/tests/test_recipes.py
+++ b/tests/test_recipes.py
@@ -49,6 +49,12 @@ def test_no_empty_code(self) -> None:
         recipe = CookBook.no_empty_code.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is True
 
+    def test_seq_exec__clean(self) -> None:
+        """If no cells are executed then no cells are executed out of order."""
+        recipe = CookBook.seq_exec.src
+        with resources.path("tests.files", "clean.ipynb") as nb:
+            assert affirm(nb_path=nb, exprs=[recipe]) is True
+
 
 class TestCookBookBad:
     """Ensure desired effect for recipes."""
@@ -60,36 +66,36 @@ def nb(self) -> Path:
             return nb
 
     def test_has_tags(self) -> None:
-        """Check fail when notebook cells have no flags."""
+        """Check failure when notebook cells have no flags."""
         recipe = CookBook.has_tags.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is False
 
     def test_has_tags_code(self) -> None:
-        """Check fail when code cells have no flags."""
+        """Check failure when code cells have no flags."""
         recipe = CookBook.has_tags_code.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is False
 
     def test_max_cells(self) -> None:
-        """Check fail when notebook has more than 128 cells."""
+        """Check failure when notebook has more than 128 cells."""
         recipe = CookBook.max_cells.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is False
 
     def test_seq_exec(self) -> None:
-        """Check fail when notebook code cells are executed out of order."""
+        """Check failure when notebook code cells are executed out of order."""
         recipe = CookBook.seq_exec.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is False
 
     def test_seq_increase(self) -> None:
-        """Check fail when notebook code cells are not executed monotonically."""
+        """Check failure when notebook code cells are not executed monotonically."""
         recipe = CookBook.seq_increase.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is False
 
     def test_startswith_md(self) -> None:
-        """Check fail when notebook's first cell is not a markdown cell."""
+        """Check failure when notebook's first cell is not a markdown cell."""
         recipe = CookBook.startswith_md.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is False
 
     def test_no_empty_code(self) -> None:
-        """Check fail when notebook contains empty code cells."""
+        """Check failure when notebook contains empty code cells."""
         recipe = CookBook.no_empty_code.src
         assert affirm(nb_path=self.nb, exprs=[recipe]) is False