Add flake8 pluin flake8 bugbear to pre-commit (TheAlgorithms#7132)

* ci(pre-commit): Add ``flake8-builtins`` additional dependency to ``pre-commit`` (TheAlgorithms#7104)

* refactor: Fix ``flake8-builtins`` (TheAlgorithms#7104)

* fix(lru_cache): Fix naming conventions in docstrings (TheAlgorithms#7104)

* ci(pre-commit): Order additional dependencies alphabetically (TheAlgorithms#7104)

* fix(lfu_cache): Correct function name in docstring (TheAlgorithms#7104)

* Update strings/snake_case_to_camel_pascal_case.py

Co-authored-by: Christian Clauss <[email protected]>

* Update data_structures/stacks/next_greater_element.py

Co-authored-by: Christian Clauss <[email protected]>

* Update digital_image_processing/index_calculation.py

Co-authored-by: Christian Clauss <[email protected]>

* Update graphs/prim.py

Co-authored-by: Christian Clauss <[email protected]>

* Update hashes/djb2.py

Co-authored-by: Christian Clauss <[email protected]>

* refactor: Rename `_builtin` to `builtin_` ( TheAlgorithms#7104)

* fix: Rename all instances (TheAlgorithms#7104)

* refactor: Update variable names (TheAlgorithms#7104)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* ci: Create ``tox.ini`` and ignore ``A003`` (TheAlgorithms#7123)

* revert: Remove function name changes (TheAlgorithms#7104)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Rename tox.ini to .flake8

* Update data_structures/heap/heap.py

Co-authored-by: Dhruv Manilawala <[email protected]>

* refactor: Rename `next_` to `next_item` (TheAlgorithms#7104)

* ci(pre-commit): Add `flake8` plugin `flake8-bugbear` (TheAlgorithms#7127)

* refactor: Follow `flake8-bugbear` plugin (TheAlgorithms#7127)

* fix: Correct `knapsack` code (TheAlgorithms#7127)

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: Christian Clauss <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Dhruv Manilawala <[email protected]>

.pre-commit-config.yaml

@@ -40,7 +40,10 @@ repos:
           - --ignore=E203,W503
           - --max-complexity=25
           - --max-line-length=88
-        additional_dependencies: [flake8-builtins, pep8-naming]
+        additional_dependencies:
+          - flake8-bugbear
+          - flake8-builtins
+          - pep8-naming
 
   - repo: https://github.com/pre-commit/mirrors-mypy
     rev: v0.982

arithmetic_analysis/jacobi_iteration_method.py

@@ -110,7 +110,7 @@ def jacobi_iteration_method(
     strictly_diagonally_dominant(table)
 
     # Iterates the whole matrix for given number of times
-    for i in range(iterations):
+    for _ in range(iterations):
         new_val = []
         for row in range(rows):
             temp = 0

arithmetic_analysis/newton_forward_interpolation.py

@@ -23,7 +23,7 @@ def ucal(u: float, p: int) -> float:
 def main() -> None:
     n = int(input("enter the numbers of values: "))
     y: list[list[float]] = []
-    for i in range(n):
+    for _ in range(n):
         y.append([])
     for i in range(n):
         for j in range(n):

arithmetic_analysis/secant_method.py

@@ -20,7 +20,7 @@ def secant_method(lower_bound: float, upper_bound: float, repeats: int) -> float
     """
     x0 = lower_bound
     x1 = upper_bound
-    for i in range(0, repeats):
+    for _ in range(0, repeats):
         x0, x1 = x1, x1 - (f(x1) * (x1 - x0)) / (f(x1) - f(x0))
     return x1
 

audio_filters/butterworth_filter.py

@@ -11,7 +11,7 @@
 
 
 def make_lowpass(
-    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)
+    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)  # noqa: B008
 ) -> IIRFilter:
     """
     Creates a low-pass filter
@@ -39,7 +39,7 @@ def make_lowpass(
 
 
 def make_highpass(
-    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)
+    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)  # noqa: B008
 ) -> IIRFilter:
     """
     Creates a high-pass filter
@@ -67,7 +67,7 @@ def make_highpass(
 
 
 def make_bandpass(
-    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)
+    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)  # noqa: B008
 ) -> IIRFilter:
     """
     Creates a band-pass filter
@@ -96,7 +96,7 @@ def make_bandpass(
 
 
 def make_allpass(
-    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)
+    frequency: int, samplerate: int, q_factor: float = 1 / sqrt(2)  # noqa: B008
 ) -> IIRFilter:
     """
     Creates an all-pass filter
@@ -121,7 +121,10 @@ def make_allpass(
 
 
 def make_peak(
-    frequency: int, samplerate: int, gain_db: float, q_factor: float = 1 / sqrt(2)
+    frequency: int,
+    samplerate: int,
+    gain_db: float,
+    q_factor: float = 1 / sqrt(2),  # noqa: B008
 ) -> IIRFilter:
     """
     Creates a peak filter
@@ -150,7 +153,10 @@ def make_peak(
 
 
 def make_lowshelf(
-    frequency: int, samplerate: int, gain_db: float, q_factor: float = 1 / sqrt(2)
+    frequency: int,
+    samplerate: int,
+    gain_db: float,
+    q_factor: float = 1 / sqrt(2),  # noqa: B008
 ) -> IIRFilter:
     """
     Creates a low-shelf filter
@@ -184,7 +190,10 @@ def make_lowshelf(
 
 
 def make_highshelf(
-    frequency: int, samplerate: int, gain_db: float, q_factor: float = 1 / sqrt(2)
+    frequency: int,
+    samplerate: int,
+    gain_db: float,
+    q_factor: float = 1 / sqrt(2),  # noqa: B008
 ) -> IIRFilter:
     """
     Creates a high-shelf filter

backtracking/sum_of_subsets.py

@@ -39,14 +39,14 @@ def create_state_space_tree(
     if sum(path) == max_sum:
         result.append(path)
         return
-    for num_index in range(num_index, len(nums)):
+    for index in range(num_index, len(nums)):
         create_state_space_tree(
             nums,
             max_sum,
-            num_index + 1,
-            path + [nums[num_index]],
+            index + 1,
+            path + [nums[index]],
             result,
-            remaining_nums_sum - nums[num_index],
+            remaining_nums_sum - nums[index],
         )
 
 

boolean_algebra/quine_mc_cluskey.py

@@ -56,7 +56,7 @@ def decimal_to_binary(no_of_variable: int, minterms: Sequence[float]) -> list[st
     temp = []
     for minterm in minterms:
         string = ""
-        for i in range(no_of_variable):
+        for _ in range(no_of_variable):
             string = str(minterm % 2) + string
             minterm //= 2
         temp.append(string)

ciphers/mixed_keyword_cypher.py

@@ -40,7 +40,7 @@ def mixed_keyword(key: str = "college", pt: str = "UNIVERSITY") -> str:
     k = 0
     for _ in range(r):
         s = []
-        for j in range(len_temp):
+        for _ in range(len_temp):
             s.append(temp[k])
             if not (k < 25):
                 break

ciphers/rabin_miller.py

@@ -11,7 +11,7 @@ def rabin_miller(num: int) -> bool:
         s = s // 2
         t += 1
 
-    for trials in range(5):
+    for _ in range(5):
         a = random.randrange(2, num - 1)
         v = pow(a, s, num)
         if v != 1:

compression/burrows_wheeler.py

@@ -154,7 +154,7 @@ def reverse_bwt(bwt_string: str, idx_original_string: int) -> str:
         )
 
     ordered_rotations = [""] * len(bwt_string)
-    for x in range(len(bwt_string)):
+    for _ in range(len(bwt_string)):
         for i in range(len(bwt_string)):
             ordered_rotations[i] = bwt_string[i] + ordered_rotations[i]
         ordered_rotations.sort()

data_structures/binary_tree/binary_search_tree_recursive.py

@@ -357,7 +357,7 @@ def test_put(self) -> None:
         assert t.root.left.left.parent == t.root.left
         assert t.root.left.left.label == 1
 
-        with self.assertRaises(Exception):
+        with self.assertRaises(Exception):  # noqa: B017
             t.put(1)
 
     def test_search(self) -> None:
@@ -369,7 +369,7 @@ def test_search(self) -> None:
         node = t.search(13)
         assert node.label == 13
 
-        with self.assertRaises(Exception):
+        with self.assertRaises(Exception):  # noqa: B017
             t.search(2)
 
     def test_remove(self) -> None:
@@ -515,7 +515,7 @@ def test_get_max_label(self) -> None:
         assert t.get_max_label() == 14
 
         t.empty()
-        with self.assertRaises(Exception):
+        with self.assertRaises(Exception):  # noqa: B017
             t.get_max_label()
 
     def test_get_min_label(self) -> None:
@@ -524,7 +524,7 @@ def test_get_min_label(self) -> None:
         assert t.get_min_label() == 1
 
         t.empty()
-        with self.assertRaises(Exception):
+        with self.assertRaises(Exception):  # noqa: B017
             t.get_min_label()
 
     def test_inorder_traversal(self) -> None:

data_structures/linked_list/circular_linked_list.py

@@ -94,25 +94,25 @@ def test_circular_linked_list() -> None:
 
     try:
         circular_linked_list.delete_front()
-        assert False  # This should not happen
+        raise AssertionError()  # This should not happen
     except IndexError:
         assert True  # This should happen
 
     try:
         circular_linked_list.delete_tail()
-        assert False  # This should not happen
+        raise AssertionError()  # This should not happen
     except IndexError:
         assert True  # This should happen
 
     try:
         circular_linked_list.delete_nth(-1)
-        assert False
+        raise AssertionError()
     except IndexError:
         assert True
 
     try:
         circular_linked_list.delete_nth(0)
-        assert False
+        raise AssertionError()
     except IndexError:
         assert True
 

data_structures/linked_list/doubly_linked_list.py

@@ -96,7 +96,7 @@ def insert_at_nth(self, index: int, data):
             self.tail = new_node
         else:
             temp = self.head
-            for i in range(0, index):
+            for _ in range(0, index):
                 temp = temp.next
             temp.previous.next = new_node
             new_node.previous = temp.previous
@@ -145,7 +145,7 @@ def delete_at_nth(self, index: int):
             self.tail.next = None
         else:
             temp = self.head
-            for i in range(0, index):
+            for _ in range(0, index):
                 temp = temp.next
             delete_node = temp
             temp.next.previous = temp.previous
@@ -194,13 +194,13 @@ def test_doubly_linked_list() -> None:
 
     try:
         linked_list.delete_head()
-        assert False  # This should not happen.
+        raise AssertionError()  # This should not happen.
     except IndexError:
         assert True  # This should happen.
 
     try:
         linked_list.delete_tail()
-        assert False  # This should not happen.
+        raise AssertionError()  # This should not happen.
     except IndexError:
         assert True  # This should happen.
 

data_structures/linked_list/middle_element_of_linked_list.py

@@ -62,7 +62,7 @@ def middle_element(self) -> int | None:
 
 if __name__ == "__main__":
     link = LinkedList()
-    for i in range(int(input().strip())):
+    for _ in range(int(input().strip())):
         data = int(input().strip())
         link.push(data)
     print(link.middle_element())

data_structures/linked_list/singly_linked_list.py

@@ -132,7 +132,7 @@ def __setitem__(self, index: int, data: Any) -> None:
         if not 0 <= index < len(self):
             raise ValueError("list index out of range.")
         current = self.head
-        for i in range(index):
+        for _ in range(index):
             current = current.next
         current.data = data
 
@@ -352,13 +352,13 @@ def test_singly_linked_list() -> None:
 
     try:
         linked_list.delete_head()
-        assert False  # This should not happen.
+        raise AssertionError()  # This should not happen.
     except IndexError:
         assert True  # This should happen.
 
     try:
         linked_list.delete_tail()
-        assert False  # This should not happen.
+        raise AssertionError()  # This should not happen.
     except IndexError:
         assert True  # This should happen.
 

data_structures/linked_list/skip_list.py

@@ -205,7 +205,7 @@ def insert(self, key: KT, value: VT):
 
             if level > self.level:
                 # After level increase we have to add additional nodes to head.
-                for i in range(self.level - 1, level):
+                for _ in range(self.level - 1, level):
                     update_vector.append(self.head)
                 self.level = level
 
@@ -407,7 +407,7 @@ def is_sorted(lst):
 
 
 def pytests():
-    for i in range(100):
+    for _ in range(100):
         # Repeat test 100 times due to the probabilistic nature of skip list
         # random values == random bugs
         test_insert()

data_structures/queue/queue_on_list.py

@@ -37,7 +37,7 @@ def get(self):
         number of times to rotate queue"""
 
     def rotate(self, rotation):
-        for i in range(rotation):
+        for _ in range(rotation):
             self.put(self.get())
 
     """Enqueues {@code item}

data_structures/queue/queue_on_pseudo_stack.py

@@ -37,7 +37,7 @@ def get(self) -> Any:
         number of times to rotate queue"""
 
     def rotate(self, rotation: int) -> None:
-        for i in range(rotation):
+        for _ in range(rotation):
             temp = self.stack[0]
             self.stack = self.stack[1:]
             self.put(temp)

data_structures/stacks/stack.py

@@ -92,13 +92,13 @@ def test_stack() -> None:
 
     try:
         _ = stack.pop()
-        assert False  # This should not happen
+        raise AssertionError()  # This should not happen
     except StackUnderflowError:
         assert True  # This should happen
 
     try:
         _ = stack.peek()
-        assert False  # This should not happen
+        raise AssertionError()  # This should not happen
     except StackUnderflowError:
         assert True  # This should happen
 
@@ -118,7 +118,7 @@ def test_stack() -> None:
 
     try:
         stack.push(200)
-        assert False  # This should not happen
+        raise AssertionError()  # This should not happen
     except StackOverflowError:
         assert True  # This should happen
 

divide_and_conquer/convex_hull.py

@@ -458,16 +458,16 @@ def convex_hull_melkman(points: list[Point]) -> list[Point]:
             convex_hull[1] = points[i]
     i += 1
 
-    for i in range(i, n):
+    for j in range(i, n):
         if (
-            _det(convex_hull[0], convex_hull[-1], points[i]) > 0
+            _det(convex_hull[0], convex_hull[-1], points[j]) > 0
             and _det(convex_hull[-1], convex_hull[0], points[1]) < 0
         ):
             # The point lies within the convex hull
             continue
 
-        convex_hull.insert(0, points[i])
-        convex_hull.append(points[i])
+        convex_hull.insert(0, points[j])
+        convex_hull.append(points[j])
         while _det(convex_hull[0], convex_hull[1], convex_hull[2]) >= 0:
             del convex_hull[1]
         while _det(convex_hull[-1], convex_hull[-2], convex_hull[-3]) <= 0: