s = "banana"
result = {ch.upper() for ch in s if s.count(ch) == 1}
print(result)

from datetime import datetime, timedelta

start = datetime(2025, 12, 31, 23, 0)
delta = timedelta(hours=2)
new_time = start + delta
print(new_time.strftime("%Y-%m-%d %H:%M"))

from datetime import datetime

d = datetime.strptime("09-06-2025 14:30", "%d-%m-%Y %H:%M")
print(d.month)

from datetime import datetime, time

t1 = time(14, 0)
t2 = datetime.strptime("13:59", "%H:%M").time()
result = t1 > t2
print(result)

import json

data = {"a": 1, "b": [2, 3]}
result = json.dumps(data)
print(result)

import json

s = '{"x": 10, "y": [1, 2]}'
obj = json.loads(s)
print(obj["y"][1])

import pickle

data = {"a": 1}
s = pickle.dumps(data)
obj = pickle.loads(s)
print(obj["a"])

import pickle

class A:
    def __init__(self):
        self.x = 42

obj = A()
s = pickle.dumps(obj)
restored = pickle.loads(s)
print(restored.x)

import json

class B:
    def __init__(self):
        self.value = 10

b = B()
print(json.dumps(b.__dict__))

import json

data = {"user": {"id": 123, "active": True}}
with open("data.json", "w") as f:
    json.dump(data, f)

with open("data.json", "r") as f:
    loaded = json.load(f)

print(loaded["user"]["id"])