Unit 9: Modules and Packages

# Form 1: Standard import
import math
print("Standard import:", math.factorial(5))

# Form 2: Aliased import
import math as m
print("Aliased import :", m.sqrt(64))

# Form 3: Direct selective import
from math import pi, ceil, floor
print(f"Direct import  : PI={pi:.4f}, Ceil={ceil(4.2)}, Floor={floor(4.8)}")

import math

# Constants
print("--- Constants ---")
print("Value of Pi (π):", math.pi)
print("Value of Euler's (e):", math.e)

# Rounding & Arithmetic
print("\n--- Arithmetic Functions ---")
print("Square Root of 144 :", math.sqrt(144))
print("Ceiling of 7.15    :", math.ceil(7.15))   # Rounds UP -> 8
print("Floor of 7.85      :", math.floor(7.85))  # Rounds DOWN -> 7
print("Power 2^5           :", math.pow(2, 5))
print("GCD of (48, 64)     :", math.gcd(48, 64))

import random

# 1. Random float between 0.0 and 1.0
print("random.random() :", round(random.random(), 4))

# 2. Random integer between [min, max] INCLUSIVE
dice_roll = random.randint(1, 6)
print("Rolling 6-sided dice:", dice_roll)

# 3. Random choice from a collection
fruits = ["Apple", "Banana", "Cherry", "Mango", "Orange"]
chosen_fruit = random.choice(fruits)
print("Randomly selected fruit:", chosen_fruit)

# 4. In-place shuffling of a list
cards = ["Ace", "King", "Queen", "Jack", "10"]
random.shuffle(cards)
print("Shuffled deck cards   :", cards)

# 5. Non-repeating sample (lottery selection)
lucky_draw = random.sample(range(1001, 1050), 3)
print("3 Lottery Winners    :", lucky_draw)

import datetime

# Current exact date and time
now = datetime.datetime.now()
print("Current Timestamp:", now)

# Formatting with strftime (String Format Time)
formatted_date = now.strftime("%A, %d %B %Y | %I:%M %p")
print("Formatted Banner :", formatted_date)

# Date Arithmetic using timedelta
today = datetime.date.today()
exam_date = today + datetime.timedelta(days=45)
print(f"Today: {today} | University Exams in 45 days: {exam_date}")

import os

# 1. Current Working Directory
current_dir = os.getcwd()
print("Current Directory:", current_dir)

# 2. Constructing cross-platform file paths (uses \ on Windows, / on Linux)
file_path = os.path.join(current_dir, "student_database.csv")
print("Constructed Path :", file_path)

# 3. Checking if file exists
exists = os.path.exists(file_path)
print(f"Does file exist? : {exists}")

# 4. Listing directory contents (first 3 items)
dir_items = os.listdir(current_dir)
print(f"Folder contains {len(dir_items)} items. First 3: {dir_items[:3]}")

import sys

# 1. Python Interpreter Version
print("Python Version:", sys.version.split()[0])
print("Running on OS :", sys.platform)

# 2. Command-Line Arguments passed to script
print("\nCommand-line arguments (sys.argv):", sys.argv)

# 3. Module Search Paths (sys.path)
print(f"\nsys.path contains {len(sys.path)} search directories.")
print("Primary search folder (CWD):", sys.path[0])

"""
Module Name: grade_calculator.py
Description: User-defined module providing grading utilities.
"""

PASSING_PERCENTAGE = 40.0  # Module Constant

def calculate_percentage(obtained, total):
    """Computes percentage rounded to 2 decimal places."""
    if total <= 0:
        return 0.0
    return round((obtained / total) * 100, 2)

def assign_letter_grade(percentage):
    """Assigns university letter grade based on percentage."""
    if percentage >= 85: return "A+"
    elif percentage >= 70: return "A"
    elif percentage >= 50: return "B"
    elif percentage >= PASSING_PERCENTAGE: return "C"
    else: return "F (Fail)"

# Self-test block: Only runs when executing this file directly!
if __name__ == "__main__":
    print("[SELF-TEST] Testing module logic...")
    test_pct = calculate_percentage(420, 500)
    print(f"[SELF-TEST] 420/500 = {test_pct}% -> Grade: {assign_letter_grade(test_pct)}")

# Importing our custom user-defined module!
import grade_calculator as gc

student_name = "Priya Sharma"
obtained_marks = 445
maximum_marks = 500

# Calling functions defined inside grade_calculator module
pct = gc.calculate_percentage(obtained_marks, maximum_marks)
grade = gc.assign_letter_grade(pct)

print(f"Student Name : {student_name}")
print(f"Marks Scored : {obtained_marks}/{maximum_marks}")
print(f"Percentage   : {pct}%")
print(f"Final Grade  : {grade}")
print(f"Pass Cutoff  : {gc.PASSING_PERCENTAGE}%")

# Style 1: Import full module path
import university_portal.examinations as exams
exams.publish_results("BCA Sem 1")

# Style 2: Import specific submodule function directly
from university_portal.finance.fee_billing import generate_receipt
receipt_id = generate_receipt(student_id=1082, amount=25000)
print("Generated Receipt ID:", receipt_id)

import math
import random
import datetime
import sys

def generate_order_id():
    """Generates a unique random order ID with current timestamp."""
    timestamp = datetime.datetime.now().strftime("%Y%m%d")
    random_suffix = random.randint(1000, 9999)
    return f"ORD-{timestamp}-{random_suffix}"

def calculate_cart_total(item_prices, discount_rate=0.10, tax_rate=0.18):
    """Calculates gross total, applies discount, and adds GST using math functions."""
    gross_amount = sum(item_prices)
    discount_amount = gross_amount * discount_rate
    discounted_subtotal = gross_amount - discount_amount
    tax_amount = discounted_subtotal * tax_rate
    
    # Using math.ceil to round up invoice cents
    final_payable = math.ceil(discounted_subtotal + tax_amount)
    
    return {
        "order_id": generate_order_id(),
        "gross": gross_amount,
        "discount": round(discount_amount, 2),
        "tax": round(tax_amount, 2),
        "total": final_payable,
        "created_at": datetime.datetime.now().strftime("%d-%b-%Y %I:%M %p")
    }

# Execution demonstration
cart_items = [499.0, 1299.0, 249.50, 850.0]
invoice = calculate_cart_total(cart_items)

print("============================================")
print(f"  INVOICE: {invoice['order_id']}")
print("============================================")
print(f"  Date & Time    : {invoice['created_at']}")
print(f"  Items Count    : {len(cart_items)}")
print(f"  Gross Subtotal : ₹{invoice['gross']:.2f}")
print(f"  Discount (10%) : -₹{invoice['discount']:.2f}")
print(f"  GST Tax (18%)  : +₹{invoice['tax']:.2f}")
print("--------------------------------------------")
print(f"  FINAL PAYABLE  : ₹{invoice['total']}")
print("============================================")