Python Code Testing और Debugging

def average(marks):
    return sum(marks) / len(marks)

def report(student):
    avg = average(student["marks"])
    return f"{student['name']}: {avg:.1f}"

print(report({"name": "Asha", "marks": [91, 88]}))
print(report({"name": "Ravi", "marks": []}))

import logging

logging.basicConfig(level=logging.INFO, format="%(levelname)-8s %(funcName)s: %(message)s")
log = logging.getLogger(__name__)

def apply_discount(price, percent):
    log.debug("raw input price=%r percent=%r", price, percent)   # hidden at INFO level
    if not 0 <= percent <= 50:
        log.warning("discount %s%% looks wrong, using 0", percent)
        percent = 0
    final = round(price * (100 - percent) / 100, 2)
    log.info("final price %s", final)
    return final

apply_discount(1200, 10)
apply_discount(1200, 90)

def grade(marks):
    total = sum(marks)
    breakpoint()            # execution stops here
    percent = total / len(marks)
    return "A" if percent >= 85 else "B"

print(grade([91, 88, 79]))

def to_paise(rupees):
    return round(rupees * 100)

assert to_paise(10) == 1000
assert to_paise(0.1 + 0.2) == 30          # floats are tricky – round() saves us
assert to_paise(99.99) == 9999
print("all checks passed")

def bill_total(items, coupon=None):
    """items: list of (price, qty). SAVE10 gives 10% off on bills of Rs 500 or more."""
    subtotal = sum(price * qty for price, qty in items)
    if coupon == "SAVE10" and subtotal > 500:
        subtotal = subtotal * 0.9
    delivery = 0 if subtotal >= 1000 else 40
    return round(subtotal + delivery)

import pytest
from bill import bill_total

def test_small_order_pays_delivery():
    assert bill_total([(100, 2)]) == 240

def test_free_delivery_from_1000():
    assert bill_total([(500, 2)]) == 1000

def test_coupon_on_exactly_500():
    assert bill_total([(250, 2)], coupon="SAVE10") == 490   # 450 + 40 delivery

@pytest.mark.parametrize("items, expected", [
    ([], 40),
    ([(99.5, 2)], 239),
    ([(300, 1), (200, 1)], 540),
])
def test_many_cases(items, expected):
    assert bill_total(items) == expected

def bill_total(items, coupon=None):
    """items: list of (price, qty). SAVE10 gives 10% off on bills of Rs 500 or more."""
    subtotal = sum(price * qty for price, qty in items)
    if coupon == "SAVE10" and subtotal >= 500:
        subtotal = subtotal * 0.9
    delivery = 0 if subtotal >= 1000 else 40
    return round(subtotal + delivery)

import pytest

def withdraw(balance, amount):
    if amount <= 0:
        raise ValueError("amount must be positive")
    if amount > balance:
        raise ValueError("insufficient balance")
    return balance - amount

def test_normal_withdraw():
    assert withdraw(1000, 300) == 700

def test_overdraw_is_blocked():
    with pytest.raises(ValueError, match="insufficient"):
        withdraw(100, 500)

import unittest

def is_valid_pin(pin):
    return len(pin) == 6 and pin.isdigit() and pin[0] != "0"

class PinTests(unittest.TestCase):
    def test_valid(self):
        self.assertTrue(is_valid_pin("302001"))

    def test_invalid(self):
        for pin in ["02001", "0123456", "30200A", ""]:
            with self.subTest(pin=pin):
                self.assertFalse(is_valid_pin(pin))

if __name__ == "__main__":
    unittest.main(verbosity=2)