"""
Урок 18. Знакомство со списками — весь код примеров одним файлом.

Источник: subjects/python-fundamentals/course/lessons/18-python-lists-intro/examples.html
Файл собран автоматически (tools/build_lesson_examples.py): правьте страницу урока.
Запуск: python lesson-18.py
"""



# ====================================================================
# Пример 1. Создание списка: литерал, list() и пустой список
# ====================================================================
literal_list = [1, 2, 3, 4, 5]
empty_list_1 = []
empty_list_2 = list()
from_string = list("python")
from_range = list(range(0, 10, 2))

print(literal_list)
print(empty_list_1, empty_list_2)
print(from_string)
print(from_range)
# [1, 2, 3, 4, 5]
# [] []
# ['p', 'y', 't', 'h', 'o', 'n']
# [0, 2, 4, 6, 8]


# ====================================================================
# Пример 2. Список хранит элементы любых типов
# ====================================================================
mixed = [42, "Python", 3.14, True, [1, 2, 3]]
print(mixed)
print(type(mixed[0]), type(mixed[1]), type(mixed[4]))
# [42, 'Python', 3.14, True, [1, 2, 3]]
# <class 'int'> <class 'str'> <class 'list'>


# ====================================================================
# Пример 3. Индексация: с начала и с конца
# ====================================================================
fruits = ["apple", "banana", "cherry", "date"]

print(fruits[0])    # apple
print(fruits[3])    # date
print(fruits[-1])   # date
print(fruits[-4])   # apple


# ====================================================================
# Пример 4. Срезы: [start:stop:step]
# ====================================================================
numbers = [0, 1, 2, 3, 4, 5, 6]

print(numbers[1:4])     # [1, 2, 3]      — с индекса 1 по 3
print(numbers[::2])     # [0, 2, 4, 6]   — каждый второй элемент
print(numbers[::-1])    # [6, 5, 4, 3, 2, 1, 0] — список в обратном порядке
print(numbers[-4:-1])   # [3, 4, 5]      — отрицательные границы
print(numbers[:])       # [0, 1, 2, 3, 4, 5, 6] — полная копия списка


# ====================================================================
# Пример 5. Изменение элемента по индексу и по срезу
# ====================================================================
items = ["pen", "pencil", "marker", "eraser"]
items[1] = "brush"
print(items)   # ['pen', 'brush', 'marker', 'eraser']

items[2:4] = ["ruler", "sharpener", "glue"]
print(items)   # ['pen', 'brush', 'ruler', 'sharpener', 'glue']


# ====================================================================
# Пример 6. len(), конкатенация + и повторение *
# ====================================================================
list1 = [1, 2, 3]
list2 = [4, 5, 6]
combined = list1 + list2
print(combined)   # [1, 2, 3, 4, 5, 6]
print(len(combined))   # 6

repeated = [1, 2, 3] * 2
print(repeated)   # [1, 2, 3, 1, 2, 3]

matrix = [[0, 0]] * 3
matrix[0][0] = 9
print(matrix)   # [[9, 0], [9, 0], [9, 0]] — изменилась КАЖДАЯ строка


# ====================================================================
# Пример 7. Проверка вхождения: in и not in
# ====================================================================
numbers = [1, 2, 3, 4, 5]
print(3 in numbers)       # True
print(6 in numbers)       # False
print(6 not in numbers)   # True

fruits = ["apple", "banana", "cherry"]
print("apple" in fruits)  # True
print("app" in fruits)    # False — ищет целый элемент, а не часть строки


# ====================================================================
# Пример 8. Перебор циклом for и вложенный цикл
# ====================================================================
words = ["cat", "dog", "bird"]

for word in words:
    print(f"Word: {word}")
    for letter in word:
        print(letter, end=" ")
    print()
# Word: cat
# c a t
# Word: dog
# d o g
# Word: bird
# b i r d


# ====================================================================
# Пример 9. Методы append, insert, extend
# ====================================================================
basket = ["apple", "banana"]
basket.append("cherry")
print(basket)   # ['apple', 'banana', 'cherry']

basket.insert(1, "kiwi")
print(basket)   # ['apple', 'kiwi', 'banana', 'cherry']

more_fruits = ["fig", "grape"]
basket.extend(more_fruits)
print(basket)   # ['apple', 'kiwi', 'banana', 'cherry', 'fig', 'grape']

basket_2 = ["apple", "banana"]
basket_2.append(more_fruits)
print(basket_2)   # ['apple', 'banana', ['fig', 'grape']] — список добавлен ЦЕЛИКОМ


# ====================================================================
# Пример 10. Методы remove и pop
# ====================================================================
colors = ["red", "green", "blue", "green"]
colors.remove("green")
print(colors)   # ['red', 'blue', 'green'] — удалилось первое вхождение

last = colors.pop()
print(last, colors)   # green ['red', 'blue']

first = colors.pop(0)
print(first, colors)   # red ['blue']

try:
    colors.remove("yellow")
except ValueError as error:
    print("ValueError:", error)
# ValueError: list.remove(x): x not in list


# ====================================================================
# Пример 11. Вложенные списки: список списков
# ====================================================================
matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
print(matrix[0])      # [1, 2, 3] — целая строка
print(matrix[1][2])   # 6 — строка 1, столбец 2

for row in matrix:
    print(row)
# [1, 2, 3]
# [4, 5, 6]
# [7, 8, 9]


# ====================================================================
# Пример 12. Границы применимости: IndexError и поведение среза
# ====================================================================
short_list = [10, 20, 30]

try:
    print(short_list[5])
except IndexError as error:
    print("IndexError:", error)
# IndexError: list index out of range

print(short_list[1:10])   # [20, 30] — срез не кидает ошибку