add handle exceptions exercises

Author: armincano

README.md

@@ -22,6 +22,8 @@
 
 ### [Iterative statements 🔃](https://colab.research.google.com/github/armincano/fullstack-python-web-dev/blob/main/m3-python-101/iterative_statements_notebook.ipynb)
 
+### [Handling exceptions 💥🤯](https://colab.research.google.com/github/armincano/fullstack-python-web-dev/blob/main/m3-python-101/handling_exceptions.ipynb)
+
 ### [Libraries 📚](https://colab.research.google.com/github/armincano/fullstack-python-web-dev/blob/main/m3-python-101/libraries_notebook.ipynb)
 
 ## Module 02: Front-end 101

m3-python-101/file-managment/open_file.py

@@ -0,0 +1,2 @@
+with open('file.txt', 'w') as file:
+    file.write('Hello, World!')

m3-python-101/handling_exceptions.ipynb

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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Handling exceptions 💥🤯"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Custom exception, and `ValueError` for an input\n",
+    "1. Design a new user-defined exception class.\n",
+    "\n",
+    "2. This class should handle the input value of a variable called salary.\n",
+    "\n",
+    "3. Ensure that the salary value is between 1000 and 2000.\n",
+    "\n",
+    "4. If the salary value is not within this range, raise an exception.\n",
+    "\n",
+    "5. The exception should indicate that the salary is not within the range of 1000 to 2000."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "The salary is 1000\n"
+     ]
+    }
+   ],
+   "source": [
+    "class SalaryNotInRange(Exception):\n",
+    "    def __init__(self, message=\"The salary must be between 1000 and 2000\"):\n",
+    "        self.__message = message\n",
+    "        super().__init__(self.__message)\n",
+    "        \n",
+    "salary = None\n",
+    "while True:\n",
+    "    try:\n",
+    "        input_salary = int(input(\"Enter a salary: \"))\n",
+    "        if input_salary not in range(1000,2001):\n",
+    "            raise SalaryNotInRange\n",
+    "        salary = input_salary\n",
+    "        break\n",
+    "    except SalaryNotInRange as e:\n",
+    "        print(e)\n",
+    "    except ValueError:\n",
+    "        print(\"The input salary must be an integer.\")\n",
+    "print(f\"The salary is {salary}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### A virtual cart"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.6"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

m3-python-101/scripts/handle-exceptions/custom_exception.py

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+"""
+1. Design a new user-defined exception class.
+2. This class should handle the input value of a variable called salary.
+3. Ensure that the salary value is between 1000 and 2000.
+4. If the salary value is not within this range, raise an exception.
+5. The exception should indicate that the salary is not within the range of 1000 to 2000.
+"""
+class SalaryNotInRange(Exception):
+    def __init__(self, message="The salary must be between 1000 and 2000"):
+        self.__message = message
+        super().__init__(self.__message)
+        
+salary = None
+while True:
+    try:
+        input_salary = int(input("Enter a salary: "))
+        if input_salary not in range(1000,2001):
+            raise SalaryNotInRange
+        salary = input_salary
+        break
+    except SalaryNotInRange as e:
+        print(e)
+    except ValueError:
+        print("The input salary must be an integer.")
+print(f"The salary is {salary}")

m3-python-101/scripts/handle-exceptions/keyerror.py

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+usuarios = {'001': 'Marca', '002': 'Mónica', '003': 'Jacob'}
+id_usuario = '004'
+try:
+    print(usuarios[id_usuario])
+except KeyError as e:
+    print(f"La clave {id_usuario} no está en el diccionario. Añadiendo clave...")
+    usuarios[id_usuario] = "Ninguno"
+    print(usuarios)

m3-python-101/scripts/handle-exceptions/validation_while_valueerror.py

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+user_age = None
+while True:
+    input_age = input("Write your age: ")
+    try:
+        user_age = int(input_age)
+        break
+    except ValueError:
+        print("The input age must be a number. Please try again.")
+
+is_adult = "You are an Adult" if user_age >= 18 else "You are not an Adult."
+print(is_adult)
+"""
+1. Design a Python program that asks the user for their age via the console.
+2. The user must enter an integer; otherwise, the program will throw an exception and ask the user to enter their age again.
+3. Next, the program should print "Adult" if the age is 18 or older; otherwise, it should print "Not an adult."
+"""

m3-python-101/scripts/handle-exceptions/zerodivisionerror.py

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+suma = 3000
+contador = 0
+try:
+    if contador == 0:
+        raise ZeroDivisionError("División por cero.")
+    division = suma / contador
+    print(division)
+except ZeroDivisionError as e:
+    print(e)

m3-python-101/virtual-cart-handle-exceptions/db.py

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+from product import Product
+
+zara_for_him_100ml= Product("for him",25990,12)
+zara_for_him_black_edition_100ml= Product("for him black edition",25990,7)
+zara_for_him_red_edition_100ml= Product("for him red edition",25990,1)
+db={}
+db.update({zara_for_him_100ml.name:zara_for_him_100ml})
+db.update({zara_for_him_black_edition_100ml.name:zara_for_him_black_edition_100ml})
+db.update({zara_for_him_red_edition_100ml.name:zara_for_him_red_edition_100ml})

m3-python-101/virtual-cart-handle-exceptions/main.py

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+from virtualcart import VirtualCart
+from db import db
+
+def main():
+    cart = VirtualCart()
+    cart.add_product("FOR HiiiM", 1)
+    cart.add_product("FOR HiM", 101)
+    cart.add_product("for him", -1)
+    # print(db["for him"].stock)
+    print("\nadd a 'for him' to the cart with quantity of 1 ↓")
+    cart.add_product("for him", 1)
+    print("show the products from the cart ↓")
+    cart.show_cart()
+    # print(db["for him"].stock)
+    print("\nadd a 'for him' to the cart with quantity of 1 ↓")
+    cart.add_product("for him", 1)
+    print("add a 'for him red edition' to the cart with quantity of 1 ↓")
+    cart.add_product("for him red edition", 1)
+    print("show the products from the cart ↓")
+    cart.show_cart()
+    print("\ncalculate total of the cart ↓")
+    print(cart.calculate_total())
+    print("\ndelete 'for him red edition' from the cart ↓")
+    cart.delete_product("for him red edition")
+    print("show the products from the cart ↓")
+    cart.show_cart()
+    print("\ncalculate total of the cart ↓")
+    print(cart.calculate_total())
+    
+if __name__ == "__main__":
+    main()

m3-python-101/virtual-cart-handle-exceptions/product.py

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+class Product:
+    def __init__(self, name:str, price:int, stock:int):
+        self.__name = name
+        self.__price = price
+        self.__stock = stock
+    
+    @property
+    def name(self):
+        return self.__name
+    @name.setter
+    def name(self, value):
+        self.__name = value
+    
+    @property
+    def price(self):
+        return self.__price
+    @price.setter
+    def price(self, value):
+        try:
+            if value < 0:
+                raise ValueError(f"You entered {value}, but Price cannot be negative")
+            self.__price = value
+        except ValueError as error:
+            print(error)
+    
+    @property
+    def stock(self):
+        return self.__stock
+    @stock.setter
+    def stock(self, value):
+        try:
+            if value < 0:
+                raise ValueError(f"You entered {value}, but Stock cannot be negative")
+            self.__stock = value
+        except ValueError as error:
+            print(error)
+            
+""" product_1=Product("Laptop", 1000, 10)
+product_1.price = -1
+product_1.price = 500
+print(product_1.price) """

m3-python-101/virtual-cart-handle-exceptions/utils/__init__.py

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+class StockInsufficientError(Exception):
+    def __init__(self, message="There is no enough stock of"):
+        self.message = message
+        super().__init__(message)
+
+class ProductNotFound(Exception):
+    def __init__(self, message="was not found in the DB."):
+        self.message = message
+        super().__init__(message)

m3-python-101/virtual-cart-handle-exceptions/utils/customexceptions.py

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+import re
+def format_currency(amount):
+    return re.sub(r'(?<!^)(?=(\d{3})+$)', r'.', f"${amount}")
+"""
+r'(?<!^)(?=(\d{3})+$)'
+1. (?<!^)
+This is a negative lookbehind assertion.
+It ensures that the position is not at the start of the string.
+This prevents the regex from matching at the beginning of the string.
+
+2. (?=(\d{3})+$)
+This is a positive lookahead assertion.
+It checks that the position is followed by one or more groups
+of exactly three digits until the end of the string.
+
+3. \d{3}
+Matches exactly three digits.
+
+3.1 (\d{3})+
+Matches one or more groups of three digits.
+
+4. $
+Asserts the position at the end of the string.
+
+In summary, this regex matches positions in the string
+where there are groups of three digits to the right,
+but not at the start of the string. This is used to insert a period .
+as a thousands separator in the currency format.
+"""

m3-python-101/virtual-cart-handle-exceptions/utils/integertolocalechile.py

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+"""
+Challenge: Shopping Cart Implementation
+Instructions
+1. Create a Base Class Product:
+1.1 It should have private attributes __name, __price, and __stock_quantity.
+1.2 It should have properties name, price, and stock_quantity to get and set the values of these attributes.
+1.3 The price property should ensure that the price is not negative.
+1.4 The stock_quantity property should ensure that the stock quantity is not negative.
+
+2. Create a Class VirtualCart:
+2.1 It should have a private attribute __products which is a dictionary where the key is the product name and the value is an instance of Product.
+2.2 It should have a method add_product(product, quantity) that adds a product to the cart.
+    - If the requested quantity exceeds the stock quantity, it should raise a custom exception InsufficientStockError.
+2.3 It should have a method remove_product(product_name) that removes a product from the cart.
+2.4 It should have a method calculate_total() that calculates and returns the total cost of the products in the cart.
+2.5 It should have a method show_cart() that prints the products in the cart with their quantities and prices.
+
+3. Testing and Verification:
+3.1 Create several products, add them to the cart, handle exceptions if you try to add more than what is in stock, calculate the total of the cart, and remove a product."""
+from product import Product
+from db import db
+from utils.customexceptions import StockInsufficientError, ProductNotFound
+from utils.integertolocalechile import format_currency
+
+class VirtualCart:
+    def __init__(self, products={}):
+        self.__products = products
+        
+    @property
+    def products(self):
+        return self.__products
+
+    def add_product(self, raw_product_name: str, quantity: int):      
+        product_name = raw_product_name.lower()
+        try:
+            if quantity <= 0:
+                raise ValueError
+            if product_name not in db:
+                raise ProductNotFound
+            if db[product_name].stock < quantity:
+                raise StockInsufficientError
+            
+            if product_name in self.__products:
+                self.__products[product_name].stock += quantity
+            else:
+                product_to_add = {product_name: Product(db[product_name].name, db[product_name].price, quantity)}
+                self.__products.update(product_to_add)
+        except ValueError:
+            print(f"Invalid quantity '{quantity}' for '{product_name}'.")
+        except ProductNotFound as e:
+            print(f"'{product_name}' {e}")
+        except StockInsufficientError as e:
+            print(f"{e} '{product_name}'.")
+    
+    def delete_product(self, raw_product_name: str):
+        product_name = raw_product_name.lower()
+        if product_name in self.__products:
+            self.__products.pop(product_name)
+            print("🗑 Product was deleted from your cart.")
+        else:
+            print("There is no product to delete")
+    
+    def calculate_total(self):
+        total = 0
+        for product in self.__products.values():
+            total += product.price * product.stock
+        return f"The total of your cart is {format_currency(total)}"
+    
+    def show_cart(self):
+        divider_1 = ">>>--->>----------------------------------------"
+        divider_2 = "----------------------------------------<<---<<<"
+        if self.__products:
+            for product in self.__products.values():
+                print(f"{divider_1}\nName: {product.name}\nPrice: {format_currency(product.price)}\nQuantity: {product.stock}\n{divider_2}")
+        else:
+            print("There are no products in your cart")