# 辞書の作成person = {    "name": "太郎",    "age": 25,    "city": "東京"}# 値へのアクセスperson["name"]   # "太郎"person["age"]    # 25

person = {"name": "太郎", "age": 25}# 値の追加・更新person["email"] = "taro@example.com"   # 新しいキーを追加person["age"] = 26                      # 既存のキーを更新# 値の削除del person["email"]# キーの存在確認"name" in person    # True"email" in person   # False# 辞書の長さlen(person)   # 2

person["phone"]   # KeyError: 'phone'# 安全なアクセスには get() を使うperson.get("phone")          # None（エラーにならない）person.get("phone", "N/A")   # "N/A"（デフォルト値を指定）

person = {"name": "太郎", "age": 25, "city": "東京"}person.keys()    # dict_keys(["name", "age", "city"])person.values()  # dict_values(["太郎", 25, "東京"])person.items()   # dict_items([("name", "太郎"), ("age", 25), ...])

person = {"name": "太郎", "age": 25}# キーのループfor key in person:    print(key)   # name, age# キーと値のループfor key, value in person.items():    print(f"{key}: {value}")# name: 太郎# age: 25

d = {"a": 1, "b": 2}# コピーd2 = d.copy()# 別の辞書をマージd.update({"c": 3, "b": 20})   # d = {"a": 1, "b": 20, "c": 3}# ポップ（取り出して削除）d.pop("a")     # 1（"a"の値を返して削除）d.pop("z", 0)  # 0（キーがない場合はデフォルト値）# 全削除d.clear()

students = [    {"name": "田中", "score": 85, "grade": "B"},    {"name": "鈴木", "score": 92, "grade": "A"},    {"name": "佐藤", "score": 78, "grade": "C"},]# 特定の学生の点数を取得for student in students:    print(f"{student['name']}: {student['score']}点")

words = ["apple", "banana", "apple", "cherry", "banana", "apple"]count = {}for word in words:    if word in count:        count[word] += 1    else:        count[word] = 1count   # {"apple": 3, "banana": 2, "cherry": 1}

words = ["apple", "banana", "apple", "cherry", "banana", "apple"]count = {}for word in words:    count[word] = count.get(word, 0) + 1count   # {"apple": 3, "banana": 2, "cherry": 1}