diff --git a/.github/workflows/pre-commit.yml b/.github/workflows/pre-commit.yml
index dd1a8a945092..27a5a97c0b6c 100644
--- a/.github/workflows/pre-commit.yml
+++ b/.github/workflows/pre-commit.yml
@@ -14,7 +14,7 @@ jobs:
             ~/.cache/pip
           key: ${{ runner.os }}-pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
       - uses: actions/setup-python@v2
-      - uses: psf/black@20.8b1
+      - uses: psf/black@21.4b0
       - name: Install pre-commit
         run: |
           python -m pip install --upgrade pip
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index b48da86ee57d..b666e88aa162 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -13,17 +13,17 @@ repos:
           )$
       - id: requirements-txt-fixer
   - repo: https://github.com/psf/black
-    rev: 20.8b1
+    rev: 21.4b0
     hooks:
       - id: black
   - repo: https://github.com/PyCQA/isort
-    rev: 5.7.0
+    rev: 5.8.0
     hooks:
       - id: isort
         args:
           - --profile=black
   - repo: https://gitlab.com/pycqa/flake8
-    rev: 3.9.0
+    rev: 3.9.1
     hooks:
       - id: flake8
         args:
diff --git a/data_structures/binary_tree/binary_search_tree.py b/data_structures/binary_tree/binary_search_tree.py
index 45c3933fe899..a1ed1d0ac2a5 100644
--- a/data_structures/binary_tree/binary_search_tree.py
+++ b/data_structures/binary_tree/binary_search_tree.py
@@ -150,7 +150,7 @@ def inorder(self, arr: list, node: Node):
             self.inorder(arr, node.right)
 
     def find_kth_smallest(self, k: int, node: Node) -> int:
-        """Return the kth smallest element in a binary search tree """
+        """Return the kth smallest element in a binary search tree"""
         arr = []
         self.inorder(arr, node)  # append all values to list using inorder traversal
         return arr[k - 1]
diff --git a/data_structures/heap/heap.py b/data_structures/heap/heap.py
index 8592362c23b9..65a70e468d1c 100644
--- a/data_structures/heap/heap.py
+++ b/data_structures/heap/heap.py
@@ -32,7 +32,7 @@ def __repr__(self) -> str:
         return str(self.h)
 
     def parent_index(self, child_idx: int) -> Optional[int]:
-        """ return the parent index of given child """
+        """return the parent index of given child"""
         if child_idx > 0:
             return (child_idx - 1) // 2
         return None
@@ -78,7 +78,7 @@ def max_heapify(self, index: int) -> None:
                 self.max_heapify(violation)
 
     def build_max_heap(self, collection: Iterable[float]) -> None:
-        """ build max heap from an unsorted array"""
+        """build max heap from an unsorted array"""
         self.h = list(collection)
         self.heap_size = len(self.h)
         if self.heap_size > 1:
@@ -87,14 +87,14 @@ def build_max_heap(self, collection: Iterable[float]) -> None:
                 self.max_heapify(i)
 
     def max(self) -> float:
-        """ return the max in the heap """
+        """return the max in the heap"""
         if self.heap_size >= 1:
             return self.h[0]
         else:
             raise Exception("Empty heap")
 
     def extract_max(self) -> float:
-        """ get and remove max from heap """
+        """get and remove max from heap"""
         if self.heap_size >= 2:
             me = self.h[0]
             self.h[0] = self.h.pop(-1)
@@ -108,7 +108,7 @@ def extract_max(self) -> float:
             raise Exception("Empty heap")
 
     def insert(self, value: float) -> None:
-        """ insert a new value into the max heap """
+        """insert a new value into the max heap"""
         self.h.append(value)
         idx = (self.heap_size - 1) // 2
         self.heap_size += 1
diff --git a/data_structures/heap/max_heap.py b/data_structures/heap/max_heap.py
index 2a08f8fa2cd1..fbc8eed09226 100644
--- a/data_structures/heap/max_heap.py
+++ b/data_structures/heap/max_heap.py
@@ -21,7 +21,7 @@ def __init__(self):
         self.__size = 0
 
     def __swap_up(self, i: int) -> None:
-        """ Swap the element up """
+        """Swap the element up"""
         temporary = self.__heap[i]
         while i // 2 > 0:
             if self.__heap[i] > self.__heap[i // 2]:
@@ -30,13 +30,13 @@ def __swap_up(self, i: int) -> None:
             i //= 2
 
     def insert(self, value: int) -> None:
-        """ Insert new element """
+        """Insert new element"""
         self.__heap.append(value)
         self.__size += 1
         self.__swap_up(self.__size)
 
     def __swap_down(self, i: int) -> None:
-        """ Swap the element down """
+        """Swap the element down"""
         while self.__size >= 2 * i:
             if 2 * i + 1 > self.__size:
                 bigger_child = 2 * i
@@ -52,7 +52,7 @@ def __swap_down(self, i: int) -> None:
             i = bigger_child
 
     def pop(self) -> int:
-        """ Pop the root element """
+        """Pop the root element"""
         max_value = self.__heap[1]
         self.__heap[1] = self.__heap[self.__size]
         self.__size -= 1
@@ -65,7 +65,7 @@ def get_list(self):
         return self.__heap[1:]
 
     def __len__(self):
-        """ Length of the array """
+        """Length of the array"""
         return self.__size
 
 
diff --git a/data_structures/linked_list/deque_doubly.py b/data_structures/linked_list/deque_doubly.py
index c9ae8b3d1ba2..2b9d70c223c4 100644
--- a/data_structures/linked_list/deque_doubly.py
+++ b/data_structures/linked_list/deque_doubly.py
@@ -9,7 +9,7 @@
 
 
 class _DoublyLinkedBase:
-    """ A Private class (to be inherited) """
+    """A Private class (to be inherited)"""
 
     class _Node:
         __slots__ = "_prev", "_data", "_next"
diff --git a/data_structures/stacks/stack.py b/data_structures/stacks/stack.py
index 840cde099d38..276684e12184 100644
--- a/data_structures/stacks/stack.py
+++ b/data_structures/stacks/stack.py
@@ -22,28 +22,28 @@ def __str__(self) -> str:
         return str(self.stack)
 
     def push(self, data):
-        """ Push an element to the top of the stack."""
+        """Push an element to the top of the stack."""
         if len(self.stack) >= self.limit:
             raise StackOverflowError
         self.stack.append(data)
 
     def pop(self):
-        """ Pop an element off of the top of the stack."""
+        """Pop an element off of the top of the stack."""
         return self.stack.pop()
 
     def peek(self):
-        """ Peek at the top-most element of the stack."""
+        """Peek at the top-most element of the stack."""
         return self.stack[-1]
 
     def is_empty(self) -> bool:
-        """ Check if a stack is empty."""
+        """Check if a stack is empty."""
         return not bool(self.stack)
 
     def is_full(self) -> bool:
         return self.size() == self.limit
 
     def size(self) -> int:
-        """ Return the size of the stack."""
+        """Return the size of the stack."""
         return len(self.stack)
 
     def __contains__(self, item) -> bool:
diff --git a/digital_image_processing/sepia.py b/digital_image_processing/sepia.py
index dfb5951676aa..e9dd2c06066d 100644
--- a/digital_image_processing/sepia.py
+++ b/digital_image_processing/sepia.py
@@ -19,7 +19,7 @@ def to_grayscale(blue, green, red):
         return 0.2126 * red + 0.587 * green + 0.114 * blue
 
     def normalize(value):
-        """ Helper function to normalize R/G/B value -> return 255 if value > 255"""
+        """Helper function to normalize R/G/B value -> return 255 if value > 255"""
         return min(value, 255)
 
     for i in range(pixel_h):
diff --git a/hashes/md5.py b/hashes/md5.py
index b7888fb610ac..b08ab957340a 100644
--- a/hashes/md5.py
+++ b/hashes/md5.py
@@ -94,7 +94,6 @@ def not32(i):
 
 
 def sum32(a, b):
-    """"""
     return (a + b) % 2 ** 32
 
 
diff --git a/machine_learning/linear_discriminant_analysis.py b/machine_learning/linear_discriminant_analysis.py
index 0d19e970e973..18553a77ad1c 100644
--- a/machine_learning/linear_discriminant_analysis.py
+++ b/machine_learning/linear_discriminant_analysis.py
@@ -283,7 +283,7 @@ def valid_input(
 
 # Main Function
 def main():
-    """ This function starts execution phase """
+    """This function starts execution phase"""
     while True:
         print(" Linear Discriminant Analysis ".center(50, "*"))
         print("*" * 50, "\n")
diff --git a/machine_learning/linear_regression.py b/machine_learning/linear_regression.py
index a726629efe00..b0bbc7b904c3 100644
--- a/machine_learning/linear_regression.py
+++ b/machine_learning/linear_regression.py
@@ -88,7 +88,7 @@ def run_linear_regression(data_x, data_y):
 
 
 def main():
-    """ Driver function """
+    """Driver function"""
     data = collect_dataset()
 
     len_data = data.shape[0]
diff --git a/maths/monte_carlo_dice.py b/maths/monte_carlo_dice.py
index e8e3abe83a99..17cedbdbcb18 100644
--- a/maths/monte_carlo_dice.py
+++ b/maths/monte_carlo_dice.py
@@ -7,7 +7,7 @@ class Dice:
     NUM_SIDES = 6
 
     def __init__(self):
-        """ Initialize a six sided dice """
+        """Initialize a six sided dice"""
         self.sides = list(range(1, Dice.NUM_SIDES + 1))
 
     def roll(self):
diff --git a/other/least_recently_used.py b/other/least_recently_used.py
index 213339636469..d0e27efc6dc8 100644
--- a/other/least_recently_used.py
+++ b/other/least_recently_used.py
@@ -4,7 +4,7 @@
 
 
 class LRUCache:
-    """ Page Replacement Algorithm, Least Recently Used (LRU) Caching."""
+    """Page Replacement Algorithm, Least Recently Used (LRU) Caching."""
 
     dq_store = object()  # Cache store of keys
     key_reference_map = object()  # References of the keys in cache