diff --git a/tract_querier/tests/test_query_eval.py b/tract_querier/tests/test_query_eval.py
index f8f3511..7783da1 100644
--- a/tract_querier/tests/test_query_eval.py
+++ b/tract_querier/tests/test_query_eval.py
@@ -1,25 +1,12 @@
 from .. import query_processor
 
+import pytest
+
 import ast
 import numpy as np
 
 
-# Ten tracts traversing random labels
-another_set = True
-while (another_set):
-    rng = np.random.default_rng()
-    tracts_labels = dict([(i, set(rng.integers(100, size=2))) for i in range(100)])
-    labels_tracts = query_processor.labels_for_tracts(tracts_labels)
-    another_set = 0 not in labels_tracts.keys() or 1 not in labels_tracts.keys()
-
-
-tracts_in_0 = set().union(*[labels_tracts[label] for label in labels_tracts if label == 0])
-tracts_in_all_but_0 = set().union(*[labels_tracts[label] for label in labels_tracts if label != 0])
-tract_in_label_0_uniquely = labels_tracts[0].difference(tracts_in_all_but_0)
-
-
 class DummySpatialIndexing:
-
     def __init__(
         self,
         crossing_tracts_labels, crossing_labels_tracts,
@@ -33,11 +20,44 @@ def __init__(
         self.label_bounding_boxes = label_bounding_boxes
         self.tract_bounding_boxes = tract_bounding_boxes
 
-dummy_spatial_indexing = DummySpatialIndexing(tracts_labels, labels_tracts, ({}, {}), ({}, {}), {}, {})
-empty_spatial_indexing = DummySpatialIndexing({}, {}, ({}, {}), ({}, {}), {}, {})
+@pytest.fixture
+def dummy_spatial_indexing():
+    # Ten tracts traversing random labels
+    another_set = True
+    while (another_set):
+        rng = np.random.default_rng()
+        tracts_labels = dict([(i, set(rng.integers(100, size=2))) for i in range(100)])
+        labels_tracts = query_processor.labels_for_tracts(tracts_labels)
+        another_set = 0 not in labels_tracts.keys() or 1 not in labels_tracts.keys()
+
+    return DummySpatialIndexing(tracts_labels, labels_tracts, ({}, {}), ({}, {}), {}, {})
+
+
+@pytest.fixture
+def tracts_in_0(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
+    return set().union(*[labels_tracts[label] for label in labels_tracts if label == 0])
+
+
+@pytest.fixture
+def tracts_in_all_but_0(dummy_spatial_indexing: DummySpatialIndexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
+    return set().union(*[labels_tracts[label] for label in labels_tracts if label != 0])
+
+
+@pytest.fixture
+def tract_in_label_0_uniquely(dummy_spatial_indexing: DummySpatialIndexing, tracts_in_all_but_0):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
+    return labels_tracts[0].difference(tracts_in_all_but_0)
+
+
+@pytest.fixture
+def empty_spatial_indexing():
+    return DummySpatialIndexing({}, {}, ({}, {}), ({}, {}), {}, {})
 
 
-def test_assign():
+def test_assign(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=0"))
     assert ((
@@ -47,7 +67,8 @@ def test_assign():
     ))
 
 
-def test_assign_attr():
+def test_assign_attr(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("a.left=0"))
     assert ((
@@ -57,7 +78,7 @@ def test_assign_attr():
     ))
 
 
-def test_assign_side():
+def test_assign_side(empty_spatial_indexing):
     query_evaluator = query_processor.EvaluateQueries(empty_spatial_indexing)
 
     queries_labels = {
@@ -92,7 +113,7 @@ def test_assign_side():
     assert {k: v.tracts for k, v in query_evaluator.evaluated_queries_info.items()} == queries_tracts
 
 
-def test_assign_str():
+def test_assign_str(empty_spatial_indexing):
     query_evaluator = query_processor.EvaluateQueries(empty_spatial_indexing)
 
     queries_labels = {
@@ -125,7 +146,7 @@ def test_assign_str():
     assert {k: v.tracts for k, v in query_evaluator.evaluated_queries_info.items()} == queries_tracts
 
 
-def test_for_list():
+def test_for_list(empty_spatial_indexing):
     query_evaluator = query_processor.EvaluateQueries(empty_spatial_indexing)
 
     queries_tracts = {
@@ -155,7 +176,7 @@ def test_for_list():
     assert {k: v.tracts for k, v in query_evaluator.evaluated_queries_info.items()} == queries_tracts
 
 
-def test_for_str():
+def test_for_str(empty_spatial_indexing):
     query_evaluator = query_processor.EvaluateQueries(empty_spatial_indexing)
 
     queries_tracts = {
@@ -185,7 +206,8 @@ def test_for_str():
     assert {k: v.tracts for k, v in query_evaluator.evaluated_queries_info.items()} == queries_tracts
 
 
-def test_add():
+def test_add(dummy_spatial_indexing: DummySpatialIndexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=0+1"))
     assert ((
@@ -195,7 +217,8 @@ def test_add():
     ))
 
 
-def test_mult():
+def test_mult(dummy_spatial_indexing: DummySpatialIndexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=0 * 1"))
     assert ((
@@ -205,7 +228,8 @@ def test_mult():
     ))
 
 
-def test_sub():
+def test_sub(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=(0 + 1) - 1"))
     assert ((
@@ -215,7 +239,8 @@ def test_sub():
     ))
 
 
-def test_or():
+def test_or(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=0 or 1"))
     assert ((
@@ -225,7 +250,8 @@ def test_or():
     ))
 
 
-def test_and():
+def test_and(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts    
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=0 and 1"))
     assert ((
@@ -235,7 +261,8 @@ def test_and():
     ))
 
 
-def test_not_in():
+def test_not_in(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts    
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=0 or 1 not in 1"))
     assert ((
@@ -245,7 +272,7 @@ def test_not_in():
     ))
 
 
-def test_only_sign():
+def test_only_sign(dummy_spatial_indexing, tract_in_label_0_uniquely):
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=~0"))
     assert ((
@@ -255,7 +282,7 @@ def test_only_sign():
     ))
 
 
-def test_only():
+def test_only(dummy_spatial_indexing, tract_in_label_0_uniquely):
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=only(0)"))
     assert ((
@@ -265,7 +292,8 @@ def test_only():
     ))
 
 
-def test_unsaved_query():
+def test_unsaved_query(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A|=0"))
     assert ((
@@ -275,7 +303,8 @@ def test_unsaved_query():
     ))
 
 
-def test_symbolic_assignment():
+def test_symbolic_assignment(dummy_spatial_indexing):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A=0; B=A"))
     assert ((
@@ -285,7 +314,8 @@ def test_symbolic_assignment():
     ))
 
 
-def test_unarySub():
+def test_unarySub(dummy_spatial_indexing, tracts_in_all_but_0):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("B=0; A=-B"))
     assert ((
@@ -295,7 +325,8 @@ def test_unarySub():
     ))
 
 
-def test_not():
+def test_not(dummy_spatial_indexing, tracts_in_all_but_0):
+    labels_tracts = dummy_spatial_indexing.crossing_labels_tracts
     query_evaluator = query_processor.EvaluateQueries(dummy_spatial_indexing)
     query_evaluator.visit(ast.parse("A= not 0"))
     assert ((