exceptions, data structures

Author: Prabhakar-Naik

basic/fibinocci.py

@@ -0,0 +1,10 @@
+def fib(n):    # write Fibonacci series up to n
+    """Print a Fibonacci series up to n."""
+    a, b = 0, 1
+    while a < n:
+        print(a, end=' ')
+        a, b = b, a+b
+    print()
+
+# Now call the function we just defined:
+fib(10)

control_structures/match_color.py

@@ -0,0 +1,18 @@
+
+from enum import Enum
+
+class Color(Enum):
+    RED = 'red'
+    GREEN = 'green'
+    BLUE = 'blue'
+
+color = Color(input("Enter your choice of 'red', 'blue' or 'green': "))
+
+match color:
+    case Color.RED:
+        print("I see red!")
+    case Color.GREEN:
+        print("Grass is green")
+    case Color.BLUE:
+        print("I'm feeling the blues :(")
+        

control_structures/match_statement.py

@@ -0,0 +1,18 @@
+def http_error(status):
+    match status:
+        case 400:
+            return "Bad request"
+        case 404:
+            return "Not found"
+        case 418:
+            return "I'm a teapot"
+        case 401 | 403 | 404:
+            return "Not allowed as a error"
+        case _:
+            return "Something's wrong with the internet"
+        
+result = http_error(400)
+print(result)
+
+result = http_error(401)
+print(result)

data_structures/list_comprehensions.py

@@ -0,0 +1,16 @@
+# Basic list comprehension
+squares = [x ** 2 for x in range(10)]
+print(squares)  # Output: [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
+
+# Conditional comprehension
+evens = [x for x in range(10) if x % 2 == 0]
+print(evens)  # Output: [0, 2, 4, 6, 8]
+
+
+# advance level
+
+def filter_even_numbers(data):
+    return [x for x in data if x % 2 == 0]
+
+my_data = [1, 2, 3, 4, 5, 6]
+print(filter_even_numbers(my_data))  # Output: [2, 4, 6]

data_structures/list_functions.py

@@ -0,0 +1,21 @@
+fruits = ['orange', 'apple', 'pear', 'banana', 'kiwi', 'apple', 'banana']
+
+print(fruits.count('apple'))
+
+print(fruits.count('tangerine'))
+
+print(fruits.index('banana'))
+
+print(fruits.index('banana', 4))  # Find next banana starting at position 4
+
+fruits.reverse()
+
+print(fruits)
+
+fruits.append('grape')
+print(fruits)
+
+fruits.sort()
+print(fruits)
+
+print(fruits.pop())

data_structures/list_slicing.py

@@ -0,0 +1,15 @@
+
+# Basic slicing
+my_list = [1, 2, 3, 4, 5]
+print(my_list[1:4])  # Output: [2, 3, 4]
+
+# Advanced slicing with step
+print(my_list[::2])  # Output: [1, 3, 5]
+
+# real time scenario
+
+def get_middle_elements(data):
+    return data[1:-1]  # Excludes the first and last elements
+
+my_data = [10, 20, 30, 40, 50]
+print(get_middle_elements(my_data))  # Output: [20, 30, 40]

data_structures/list_stack.py

@@ -0,0 +1,14 @@
+stack = [3, 4, 5]
+stack.append(6)
+stack.append(7)
+
+print(stack)
+
+stack.pop()
+
+print(stack)
+
+stack.pop()
+
+stack.pop()
+print(stack)

data_structures/tuples.py

@@ -0,0 +1,20 @@
+my_tuple = (1, 2, 3)
+
+try:
+    print(my_tuple[3])  # Output: 2
+except IndexError as e:
+    print("error occured:",e)
+
+
+# advance level
+
+def get_min_max(data):
+    return (min(data), max(data))
+
+try:
+    my_data = [10, 20, 30, 40, 50,-7]
+    print(get_min_max(my_data))  # Output: (10, 50)
+except ValueError as e:
+    print("Error occured:",e)
+    
+    

exceptions/custom_exceptions.py

@@ -0,0 +1,8 @@
+class CustomError(Exception):
+    def __init__(self, message):
+        self.message = message
+
+try:
+    raise CustomError("This is a custom error.")
+except CustomError as e:
+    print("Caught a custom error:", e.message)

exceptions/file_operations.py

@@ -0,0 +1,11 @@
+try:
+    file = open("example1.txt", "r")
+    content = file.read()
+except FileNotFoundError:
+    print("File not found.")
+else:
+    print("File content:", content)
+finally:
+    if 'file' in locals():
+        file.close()
+    print("File operation completed.")

exceptions/multiple_exceptions.py

@@ -0,0 +1,26 @@
+try:
+    result = 10 / 0
+    print(result)
+except (ZeroDivisionError, ValueError) as e:
+    print("Error occurred:", e)
+    
+
+# another example
+
+def get_positive_number(number):
+    if number <= 0:
+        raise ValueError("The number must be positive.")
+    return number
+
+try:
+    number = get_positive_number("uyu")
+    print(number)
+except (ValueError, TypeError) as e:
+    print("Caught an error:", e)
+
+
+# another example
+try:
+    value = int("abc")  # This will raise a ValueError because "abc" is not a valid integer.
+except TypeError as e:
+    print("Caught an error:", e)

exceptions/validate_error_custom_exception.py

@@ -0,0 +1,16 @@
+class ValidationError(Exception):
+    def __init__(self, message):
+        self.message = message
+
+def validate_age(age):
+    if age < 0:
+        raise ValidationError("Age cannot be negative.")
+    elif age == 0:
+        raise ValidationError("Age cannot be zero")
+    else:
+        print("Valid age:", age)
+
+try:
+    validate_age(20)
+except ValidationError as e:
+    print("Validation error:", e.message)