diff --git a/pydatastructs/linear_data_structures/tests/test_arrays.py b/pydatastructs/linear_data_structures/tests/test_arrays.py
index 0114ef72a..1a65d696f 100644
--- a/pydatastructs/linear_data_structures/tests/test_arrays.py
+++ b/pydatastructs/linear_data_structures/tests/test_arrays.py
@@ -11,14 +11,14 @@ def test_OneDimensionalArray():
     assert ODA(int, [1.0, 2, 3, 4, 5], 5)
     assert ODA(int, 5)
     assert ODA(int, [1.0, 2, 3])
-    raises(IndexError, lambda: A[7])
-    raises(IndexError, lambda: A[-1])
-    raises(ValueError, lambda: ODA())
-    raises(ValueError, lambda: ODA(int, 1, 2, 3))
-    raises(TypeError, lambda: ODA(int, 5.0, set([1, 2, 3])))
-    raises(TypeError, lambda: ODA(int, 5.0))
-    raises(TypeError, lambda: ODA(int, set([1, 2, 3])))
-    raises(ValueError, lambda: ODA(int, 3, [1]))
+    assert raises(IndexError, lambda: A[7])
+    assert raises(IndexError, lambda: A[-1])
+    assert raises(ValueError, lambda: ODA())
+    assert raises(ValueError, lambda: ODA(int, 1, 2, 3))
+    assert raises(TypeError, lambda: ODA(int, 5.0, set([1, 2, 3])))
+    assert raises(TypeError, lambda: ODA(int, 5.0))
+    assert raises(TypeError, lambda: ODA(int, set([1, 2, 3])))
+    assert raises(ValueError, lambda: ODA(int, 3, [1]))
 
 def test_DynamicOneDimensionalArray():
     DODA = DynamicOneDimensionalArray
diff --git a/pydatastructs/miscellaneous_data_structures/tests/test_stack.py b/pydatastructs/miscellaneous_data_structures/tests/test_stack.py
index 614b51637..2522089be 100644
--- a/pydatastructs/miscellaneous_data_structures/tests/test_stack.py
+++ b/pydatastructs/miscellaneous_data_structures/tests/test_stack.py
@@ -10,16 +10,16 @@ def test_Stack():
     s.push(3)
     assert s.top == 3
     assert str(s) == '[1, 2, 3]'
-    raises(ValueError, lambda: s.push(4))
+    assert raises(ValueError, lambda: s.push(4))
     assert s.pop() == 3
     assert s.pop() == 2
     assert s.pop() == 1
     assert s.top == 0
-    raises(ValueError, lambda: s.pop())
-    raises(ValueError, lambda: Stack())
-    raises(TypeError, lambda: Stack(maxsize=8, top=3.5))
-    raises(ValueError, lambda: Stack(maxsize=5, top=0, items=[1, 2, 3]))
-    raises(ValueError, lambda: Stack(maxsize=5, top=0,
+    assert raises(ValueError, lambda: s.pop())
+    assert raises(ValueError, lambda: Stack())
+    assert raises(TypeError, lambda: Stack(maxsize=8, top=3.5))
+    assert raises(ValueError, lambda: Stack(maxsize=5, top=0, items=[1, 2, 3]))
+    assert raises(ValueError, lambda: Stack(maxsize=5, top=0,
                         items=OneDimensionalArray(int, 6)))
-    raises(NotImplementedError, lambda: Stack(implementation='',
+    assert raises(NotImplementedError, lambda: Stack(implementation='',
                                     maxsize=5, top=0))
diff --git a/pydatastructs/trees/tests/test_binary_trees.py b/pydatastructs/trees/tests/test_binary_trees.py
index 15aef8f97..2ebef336b 100644
--- a/pydatastructs/trees/tests/test_binary_trees.py
+++ b/pydatastructs/trees/tests/test_binary_trees.py
@@ -96,9 +96,9 @@ def test_BinaryTreeTraversal():
          "(None, 'A', 'A', None)", "(5, 'D', 'D', 6)", "(8, 'I', 'I', None)",
          "(None, 'C', 'C', None)", "(None, 'E', 'E', None)",
          "(None, 'H', 'H', None)"]
-    raises(NotImplementedError, lambda: trav.breadth_first_search(strategy='iddfs'))
-    raises(NotImplementedError, lambda: trav.depth_first_search(order='in_out_order'))
-    raises(TypeError, lambda: BTT(1))
+    assert raises(NotImplementedError, lambda: trav.breadth_first_search(strategy='iddfs'))
+    assert raises(NotImplementedError, lambda: trav.depth_first_search(order='in_out_order'))
+    assert raises(TypeError, lambda: BTT(1))
 
 def test_AVLTree():
     a = AVLTree('M', 'M')
@@ -229,8 +229,8 @@ def test_AVLTree():
     a5.tree[12].size = 1
     a5.tree[13].size = 1
 
-    raises(ValueError, lambda: a5.select(0))
-    raises(ValueError, lambda: a5.select(15))
+    assert raises(ValueError, lambda: a5.select(0))
+    assert raises(ValueError, lambda: a5.select(15))
     assert a5.rank(-1) == None
     def test_select_rank(expected_output):
         output = []
diff --git a/pydatastructs/trees/tests/test_space_partitioning_tree.py b/pydatastructs/trees/tests/test_space_partitioning_tree.py
index 586ced204..4e202b401 100644
--- a/pydatastructs/trees/tests/test_space_partitioning_tree.py
+++ b/pydatastructs/trees/tests/test_space_partitioning_tree.py
@@ -17,4 +17,4 @@ def test_OneDimensionalSegmentTree():
     assert segt.cache == True
     assert len(segt.query(-1)) == 0
     assert len(segt.query(2.8)) == 2
-    raises(ValueError, lambda: ODST([(1, 2, 3)]))
+    assert raises(ValueError, lambda: ODST([(1, 2, 3)]))