Day 9 – 字典与嵌套

字典

基本语法

字典是由键值对组成，基本的语法如下

{key1:value1, key2: value2, ...}

示例

# 字典示例
colors = {
	"apple": "red",
	"pear": "green",
	"banana": "yellow"
}

基本使用

字典的基本使用，如下所示

# 获取字典中的元素 dictionary_name[key]
print(colors["apple"]) # red

# 创建空字典 {}
empty_dictionary = {}

# 修改字典中元素的值
colours["apple"] = "green"

# 遍历字典的键
for key in colors:
    print(key)

# 遍历字典中的值
for key in colors:
    print(colors[key])

# 同时遍历 key value
for key, value in colors.items():
    print(key, value)

嵌套

字典中嵌套列表或者字典，或者列表中嵌套列表。基本的嵌套如下所示

{
	key: [list],
	key2: {Dict},
}

代码示例

# 字典嵌套列表
travel_log = {
    "France": ["Pairs", "Lille"],
    "Germany": ["Stuttgart", "Berlin"],
}

# 打印 Lille
print(travel_log["France"][1])

# 列表嵌套列表
nested_list = ["A", "B", ["C", "D"]]
print(nested_list[2][1]) # D

# 字典嵌套字典
travel_log = {
  "France": {
    "cities_visited": ["Paris", "Lille", "Dijon"],
    "total_visits": 12
   },
  "Germany": {
    "cities_visited": ["Berlin", "Hamburg", "Stuttgart"],
    "total_visits": 5
   },
}

print(travel_log["Germany"]["cities_visited"][2]) # Stuttgart

秘密竞拍

秘密竞拍游戏的流程图，如下所示

from art import logo
print(logo)


def find_highest_bidder(bidding_record):
    highest_bid = 0
    winner = ""
    for bidder in bidding_record:
        bid_amount = bidding_record[bidder]
        if bid_amount > highest_bid:
            highest_bid = bid_amount
            winner = bidder
    print(f"The winner is {winner} with a bid of ${highest_bid}")


bids = {}
continue_bidding = True
while continue_bidding:
    name = input("What is your name?: ")
    price = int(input("What is your bid?: $"))
    bids[name] = price
    should_continue = input("Are there any other bidders? Type 'yes or 'no'.\n")
    if should_continue == "no":
        continue_bidding = False
        find_highest_bidder(bids)
    elif should_continue == "yes":
        print("\n" * 20)