from datetime import date, time, datetime d = date(2026, 11, 2)t = time(9, 30, 15)dt = datetime(2026, 11, 2, 9, 30, 15) print(d, t, dt)print(d.year, d.month, d.day, d.weekday())   # Monday is 0print(dt.date(), dt.time())

2026-11-02 09:30:15 2026-11-02 09:30:15
2026 11 2 0
2026-11-02 09:30:15

from datetime import date, datetime today = date.today()now = datetime.now()print(type(today).__name__, type(now).__name__)print(today == now.date())

date datetime
True

from datetime import datetime dt = datetime(2026, 11, 2, 14, 5, 9)print(dt.strftime("%d-%m-%Y"))print(dt.strftime("%A, %d %B %Y"))print(dt.strftime("%I:%M %p"))print(dt.isoformat())print(f"{dt:%Y/%m/%d %H:%M}")

02-11-2026
Monday, 02 November 2026
02:05 PM
2026-11-02T14:05:09
2026/11/02 14:05

from datetime import datetime, date dt = datetime.strptime("02/11/2026 18:45", "%d/%m/%Y %H:%M")print(dt, dt.hour) print(date.fromisoformat("2026-12-25"))

2026-11-02 18:45:00 18
2026-12-25

from datetime import datetimedatetime.strptime("2026-11-02", "%d/%m/%Y")

Traceback (most recent call last):
  File "main.py", line 2, in <module>
    datetime.strptime("2026-11-02", "%d/%m/%Y")
    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python3\Lib\_strptime.py", line 844, in _strptime_datetime_datetime
    tt, fraction, gmtoff_fraction = _strptime(data_string, format)
                                    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python3\Lib\_strptime.py", line 574, in _strptime
    raise ValueError("time data %r does not match format %r" %
                     (data_string, format))
ValueError: time data '2026-11-02' does not match format '%d/%m/%Y'

from datetime import date, timedelta start = date(2026, 11, 2)print(start + timedelta(days=30))print(start - timedelta(weeks=2)) deadline = date(2026, 12, 31)remaining = deadline - start          # subtracting dates gives a timedeltaprint(remaining, remaining.days)

2026-12-02
2026-10-19
59 days, 0:00:00 59

from datetime import datetime, timedelta login = datetime(2026, 11, 2, 9, 15)logout = datetime(2026, 11, 2, 17, 40)worked = logout - loginprint(worked)print(worked.total_seconds() / 3600, "hours")

8:25:00
8.416666666666666 hours

from datetime import date dates = [date(2026, 3, 1), date(2025, 12, 25), date(2026, 1, 15)]print(sorted(dates))print(max(dates), date(2026, 1, 1) < date(2026, 1, 2))

[datetime.date(2025, 12, 25), datetime.date(2026, 1, 15), datetime.date(2026, 3, 1)]
2026-03-01 True

from datetime import date def age_on(birth, on_day):    years = on_day.year - birth.year    if (on_day.month, on_day.day) < (birth.month, birth.day):        years -= 1          # birthday not reached yet this year    return years print(age_on(date(1995, 12, 20), date(2026, 11, 2)))print(age_on(date(1995, 6, 1), date(2026, 11, 2)))

30
31

from datetime import datetime, timezone, timedelta utc_time = datetime(2026, 11, 2, 12, 0, tzinfo=timezone.utc)ist = timezone(timedelta(hours=5, minutes=30))print(utc_time.astimezone(ist))print(utc_time.astimezone(ist).strftime("%H:%M %z"))

2026-11-02 17:30:00+05:30
17:30 +0530

from datetime import datetime, timezone dt = datetime(2026, 1, 1, tzinfo=timezone.utc)ts = dt.timestamp()print(ts)print(datetime.fromtimestamp(ts, tz=timezone.utc))

1767225600.0
2026-01-01 00:00:00+00:00

import sys print("script:", sys.argv[0])print("arguments:", sys.argv[1:]) if len(sys.argv) > 1:    name = sys.argv[1]    times = int(sys.argv[2]) if len(sys.argv) > 2 else 1    for _ in range(times):        print("Hello,", name)

$ python greet.py Asha 2script: greet.pyarguments: ['Asha', '2']Hello, AshaHello, Asha$ python greet.pyscript: greet.pyarguments: []

import sys def main(values):    if not values:        print("no values given", file=sys.stderr)        sys.exit(2)    print("total:", sum(map(int, values))) main(sys.argv[1:])

$ python check.py 4 5 6total: 15$ python check.pyno values given$ python -c "import subprocess, sys; print('exit code:', subprocess.run([sys.executable, 'check.py']).returncode)"no values givenexit code: 2

import sys print(sys.version_info.major, sys.version_info.minor)print(sys.version_info >= (3, 10))print(sys.platform)print(sys.maxsize == 2 ** 63 - 1)

3 15
True
win32
True

import sys if sys.version_info < (3, 10):    sys.exit("This script needs Python 3.10 or newer")print("version OK")

version OK

import sys print(type(sys.path).__name__, len(sys.path) > 2)print(any(p.endswith("site-packages") for p in sys.path))

list True
True

import sys sys.stdout.write("normal output\n")print("also normal output", file=sys.stdout)print("number of bytes written:", sys.stdout.write("abc\n"))

normal output
also normal output
abc
number of bytes written: 4

import sys numbers = [int(line) for line in sys.stdin if line.strip()]print("sum:", sum(numbers))

sum: 30

import sys print(sys.getrecursionlimit())print(sys.getsizeof([]) < sys.getsizeof([1, 2, 3]))print(sys.executable.endswith(("python.exe", "python", "python3")))

1000
True
True

from collections import Counter words = "the cat and the hat and the bat".split()counts = Counter(words)print(counts)print(counts["the"], counts["dog"])     # missing items count as 0print(counts.most_common(2))

Counter({'the': 3, 'and': 2, 'cat': 1, 'hat': 1, 'bat': 1})
3 0
[('the', 3), ('and', 2)]

from collections import Counter print(Counter("mississippi").most_common(3)) week1 = Counter(passed=40, failed=5)week2 = Counter(passed=42, failed=2, skipped=1)print(week1 + week2)print(sorted((week1 + week2).elements())[:3])

[('i', 4), ('s', 4), ('p', 2)]
Counter({'passed': 82, 'failed': 7, 'skipped': 1})
['failed', 'failed', 'failed']

from collections import Counterprint(Counter("listen") == Counter("silent"), Counter("apple") == Counter("paple"))

True True

from collections import defaultdict employees = [("qa", "Asha"), ("dev", "Ravi"), ("qa", "Meena"), ("ops", "John")] teams = defaultdict(list)for team, name in employees:    teams[team].append(name)       # no need to check if the key exists print(dict(teams)) letters = defaultdict(int)for ch in "banana":    letters[ch] += 1print(dict(letters))

{'qa': ['Asha', 'Meena'], 'dev': ['Ravi'], 'ops': ['John']}
{'b': 1, 'a': 3, 'n': 2}

from collections import deque queue = deque(["task1", "task2"])queue.append("task3")          # join at the backqueue.appendleft("urgent")     # jump the queueprint(queue) print(queue.popleft())         # serve from the frontprint(queue.pop())             # remove from the backprint(queue)

deque(['urgent', 'task1', 'task2', 'task3'])
urgent
task3
deque(['task1', 'task2'])

from collections import deque recent = deque(maxlen=3)for page in ["home", "search", "product", "cart", "checkout"]:    recent.append(page)print(list(recent)) d = deque([1, 2, 3, 4, 5])d.rotate(2)print(d)

['product', 'cart', 'checkout']
deque([4, 5, 1, 2, 3])

from collections import namedtuple Employee = namedtuple("Employee", ["name", "dept", "salary"])e = Employee("Asha", "QA", 52000) print(e)print(e.name, e.salary)print(e._asdict())print(e._replace(salary=56000))

Employee(name='Asha', dept='QA', salary=52000)
Asha 52000
{'name': 'Asha', 'dept': 'QA', 'salary': 52000}
Employee(name='Asha', dept='QA', salary=56000)

from collections import OrderedDict cache = OrderedDict(a=1, b=2, c=3)cache.move_to_end("a")print(list(cache))cache.popitem(last=False)      # remove the oldestprint(list(cache))

['b', 'c', 'a']
['c', 'a']

from collections import ChainMap defaults = {"browser": "chromium", "headless": True, "timeout": 30}env = {"headless": False}cli = {"timeout": 60} settings = ChainMap(cli, env, defaults)print(settings["browser"], settings["headless"], settings["timeout"])

chromium False 60

def average(values):    return sum(values) / len(values) print(average([10, 20]))print(average([]))

15.0
Traceback (most recent call last):
  File "main.py", line 5, in <module>
    print(average([]))
          ~~~~~~~^^^^
  File "main.py", line 2, in average
    return sum(values) / len(values)
           ~~~~~~~~~~~~^~~~~~~~~~~~~
ZeroDivisionError: division by zero

text = "12a"try:    number = int(text)    print("Parsed", number)except ValueError:    print(f"{text!r} is not a number")print("program continues")

'12a' is not a number
program continues

def safe_divide(a, b):    try:        return a / b    except ZeroDivisionError:        return "cannot divide by zero"    except TypeError as e:        return f"bad input: {e}" print(safe_divide(10, 4))print(safe_divide(10, 0))print(safe_divide(10, "2"))

2.5
cannot divide by zero
bad input: unsupported operand type(s) for /: 'int' and 'str'

data = {"items": [1, 2]}for key, index in [("items", 5), ("users", 0)]:    try:        print(data[key][index])    except (KeyError, IndexError) as e:        print(type(e).__name__, e)

IndexError list index out of range
KeyError 'users'

def read_number(text):    try:        n = int(text)    except ValueError:        print("  invalid:", text)    else:        print("  valid:", n)    finally:        print("  done with", repr(text)) read_number("42")read_number("x")

  valid: 42
  done with '42'
  invalid: x
  done with 'x'

def set_age(age):    if not isinstance(age, int):        raise TypeError(f"age must be an int, got {type(age).__name__}")    if age < 0:        raise ValueError("age cannot be negative")    return age for value in [30, -1, "30"]:    try:        print("ok", set_age(value))    except (TypeError, ValueError) as e:        print("rejected:", e)

ok 30
rejected: age cannot be negative
rejected: age must be an int, got str

try:    {}["missing"]except KeyError:    print("logging the error, then passing it on")    raise

logging the error, then passing it on
Traceback (most recent call last):
  File "main.py", line 2, in <module>
    {}["missing"]
    ~~^^^^^^^^^^^
KeyError: 'missing'

class InsufficientFundsError(Exception):    def __init__(self, balance, amount):        super().__init__(f"need {amount}, only {balance} available")        self.balance = balance        self.amount = amount def withdraw(balance, amount):    if amount > balance:        raise InsufficientFundsError(balance, amount)    return balance - amount try:    withdraw(500, 800)except InsufficientFundsError as e:    print("Declined:", e)    print("Short by", e.amount - e.balance)

Declined: need 800, only 500 available
Short by 300

def load_port(config):    try:        return int(config["port"])    except (KeyError, ValueError) as e:        raise RuntimeError("invalid config: port") from e load_port({"port": "eighty"})

Traceback (most recent call last):
  File "main.py", line 3, in load_port
    return int(config["port"])
ValueError: invalid literal for int() with base 10: 'eighty'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "main.py", line 7, in <module>
    load_port({"port": "eighty"})
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "main.py", line 5, in load_port
    raise RuntimeError("invalid config: port") from e
RuntimeError: invalid config: port

attempts = iter(["timeout", "timeout", "ok"]) def call_api():    result = next(attempts)    if result == "timeout":        raise TimeoutError("server did not answer")    return "200 OK" for attempt in range(1, 4):    try:        print(call_api(), "on attempt", attempt)        break    except TimeoutError as e:        print(f"attempt {attempt}: {e}")

attempt 1: server did not answer
attempt 2: server did not answer
200 OK on attempt 3