{
     "pandas": {
       "1.1.0": { "depends": { "numpy": ">=1.17,<1.20" } },
       "1.3.5": { "depends": { "numpy": ">=1.19,<1.22", "python-dateutil": ">=2.7" } }
     },
     "numpy": {
       "1.18.5": { "depends": {} },
       "1.19.2": { "depends": {} },
       "1.21.0": { "depends": {} }
     },
     "python-dateutil": {
       "2.8.0": { "depends": { "six": ">=1.5" } },
       "2.8.2": { "depends": { "six": ">=1.5" } }
     },
     "six": {
       "1.14.0": { "depends": {} },
       "1.16.0": { "depends": {} }
     }
   }
   

   pandas>=1.1,<1.4
   python-dateutil==2.8.2
   

resolve(catalog: dict[str, dict[str, dict]],
        requirements: list[str]) -> dict[str, str]

t"Привет, {name}!"

from string.templatelib import Template

user_input = "<script>alert('XSS')</script>"
template = t"<p>{user_input}</p>"

# Предположим, функция html() экранирует опасные символы
safe_output = html(template)

# Опасный подход с f-строкой
query = f"SELECT * FROM users WHERE name = '{user_input}'"

def update_dict(key, value, d={}):
    d[key] = value
    return d

dict1 = update_dict('a', 1)
dict2 = update_dict('b', 2, {})
dict3 = update_dict('c', 3)

print("dict1 =", dict1)
print("dict2 =", dict2)
print("dict3 =", dict3)

dict1 = {'a': 1}  
dict2 = {'b': 2}  
dict3 = {'c': 3}

dict1 = {'a': 1, 'c': 3}  
dict2 = {'b': 2}  
dict3 = {'a': 1, 'c': 3}

dict1 = {'a': 1}  
dict2 = {'b': 2}  
dict3 = {'a': 1, 'c': 3}

from collections import defaultdict

actions = defaultdict(list)

def track(user_id, action):
    actions[user_id].append(action)

track('alice', 'login')
track('bob', 'view')
track('alice', 'logout')

# Теперь вы хотите скопировать этот словарь
copy_actions = actions.copy()

# Допишем в оригинал
track('bob', 'logout')

# Посмотрим, как выглядит копия
print(copy_actions['bob'])  # Что будет напечатано?

c = counter(10)
print(c())  # 11
print(c())  # 12
print(c())  # 13

d = counter(100)
print(d())  # 101
print(c())  # 14  ← работает независимо

def counter(start):
    count = start
    def inner():
        nonlocal count
        count += 1
        return count
    return inner

# Проверка
a = counter(5)
print(a())  # 6
print(a())  # 7

b = counter(100)
print(b())  # 101
print(a())  # 8

def append_to_list(value, my_list=[]):
    my_list.append(value)
    return my_list

print(append_to_list(1))
print(append_to_list(2))
print(append_to_list(3))

[1]
[1, 2]
[1, 2, 3]

def append_to_list(value, my_list=None):
    if my_list is None:
        my_list = []
    my_list.append(value)
    return my_list

[1]
[2]
[3]

funcs = []

for i in range(5):
    funcs.append(lambda: i)

results = [f() for f in funcs]
print(results)

[4, 4, 4, 4, 4]

for i in range(5):
    funcs.append(lambda i=i: i)

[0, 1, 2, 3, 4]