Python notes

PTHARRISH · PTHARRISH · commit f245d8cd08d3 · 2025-11-14T20:54:46.000+05:30
diff --git a/DSA/Searching Algorithm/Binary_search.py b/DSA/Searching Algorithm/Binary_search.py
@@ -1,25 +1,25 @@
-def binarysearch(arr,target):
-    low,high=0,len(arr)-1
-    while low<=high:
-        mid=(low+high)//2
-        if arr[mid]==target:
+def binarysearch(arr, target):
+    low, high = 0, len(arr) - 1
+    while low <= high:
+        mid = (low + high) // 2
+        if arr[mid] == target:
             return mid
-        elif arr[mid]<target:
-            low=mid+1
+        elif arr[mid] < target:
+            low = mid + 1
         else:
-            high=mid-1
+            high = mid - 1
     return -1
 
 
-arr=[int(x) for x in input("Enter the value: ").split(",")]
-target=int(input("enter the target value: "))
-print(binarysearch(arr,target))
+arr = [int(x) for x in input("Enter the value: ").split(",")]
+target = int(input("enter the target value: "))
+print(binarysearch(arr, target))
 
 
 # Binary search
 
-# Divide the search space into two halves by finding the middle index “mid”. 
-# Compare the middle element of the search space with the key. 
+# Divide the search space into two halves by finding the middle index “mid”.
+# Compare the middle element of the search space with the key.
 # If the key is found at middle element, the process is terminated.
 # If the key is not found at middle element, choose which half will be used as the next search space.
 # If the key is smaller than the middle element, then the left side is used for next search.
@@ -71,7 +71,7 @@ def binarysearch(arr,target):
 # else:
 # 	print("Element is not present in array")
 
-# Time Complexity: 
+# Time Complexity:
 # Best Case: O(1)
 # Average Case: O(log N)
 # Worst Case: O(log N)
@@ -104,10 +104,7 @@ def binarysearch(arr,target):
 #     return -1
 
 
-
 # arr=[int(x)for x in input('array').split(",")]
 # v=int(input())
 # result=search(arr,0,len(arr),v)
 # print(result)
-
-
diff --git a/DSA/Sorting Algorithm/quick sort.py b/DSA/Sorting Algorithm/quick sort.py
@@ -78,3 +78,13 @@ def quick_sort(arr):
 
 arr = [700, 200, 400, 100, 90]
 print(quick_sort(arr))
+
+
+def quick_sort(arr):
+    if len(arr) == 1:
+        return arr
+    pivot = arr[len(arr) // 2]
+    left = [x for x in arr if x < pivot]
+    pivot = [x for x in arr if x == pivot]
+    right = [x for x in arr if x > pivot]
+    return quick_sort(left) + pivot + quick_sort(right)
diff --git a/Notes/Multi_threading.py b/Notes/Multi_threading.py
@@ -0,0 +1,12 @@
+# Multi-threading in Python:
+# In Python, multithreading allows you to run multiple threads concurrently within a single process,
+# which is also known as thread-based parallelism.
+# This means a program can perform multiple tasks at the same time,
+# enhancing its efficiency and responsiveness.
+
+# Multithreading in Python is especially useful for multiple I/O-bound operations,
+# rather than for tasks that require heavy computation.
+
+# Generally, a computer program sequentially executes the instructions,
+# from start to the end. Whereas,
+# Multithreading divides the main task into more than one sub-task and executes them in an overlapping manner.
diff --git a/Notes/decorator.py b/Notes/decorator.py
@@ -0,0 +1,41 @@
+# Decorators in Python
+# A decorator is a function that takes another function as an argument,
+# extends its behavior, and returns a new function.
+# Decorators are often used to add functionality to existing functions
+# without modifying their code.
+
+
+def decorator_function(original_function):
+    def wrapper_function(*args, **kwargs):
+        print("Wrapper executed this before {}".format(original_function.__name__))
+        return original_function(*args, **kwargs)
+
+    return wrapper_function
+
+
+@decorator_function
+def display():
+    print("Display function executed.")
+
+
+display()
+
+
+# example 2:
+def login_required(func):
+    def wrapper(*args, **kwargs):
+        if args[0] == "admin":
+            return func(*args, **kwargs)
+        else:
+            return "Access Denied"
+
+    return wrapper
+
+
+@login_required
+def view_dashboard(user):
+    return "Welcome to the dashboard!"
+
+
+print(view_dashboard("admin"))  # Output: Welcome to the dashboard!
+print(view_dashboard("guest"))  # Output: Access Denied
diff --git a/Notes/thread.py b/Notes/thread.py
