Python中如何按指定id选中对应字典并更新其内容？

你现有代码的更新逻辑默认仅能修改最后一条录入的交易记录，只要在更新分支新增目标交易ID的录入和校验逻辑即可实现按指定ID修改的需求，修改后的完整代码如下：

cont = {}
n = int(input("Insert the number of transactions:"))

if n == 0:
    print("Going to the next option")
else:
    for i in range(0, n):
        tranz = input("Insert the id of the transaction: ")
        ziua = input("Insert the day: ")
        suma = input("Insert the amount: ")
        tipul = input("Insert the type(int/out): ")
        # 原有代码中未使用的tranz_key变量可直接删除
        cont[tranz] = {"day": ziua, "amount": suma, "type": tipul}


k = input("Do you wish to update something?(Yes/No): ")


if k == 'No':
    print("Going to the next option")
else:
    # 新增：获取用户要修改的目标交易ID
    target_id = input("Insert the ID of the transaction you want to modify: ")
    # 校验ID是否存在，避免KeyError报错
    if target_id not in cont:
        print(f"Transaction ID {target_id} does not exist!")
    else:
        y = input("Insert a new day (leave blank to keep original value):")
        if len(y) != 0:
            cont[target_id].update({"day": y})
        z = input("Insert a new amount (leave blank to keep original value):")
        if len(z) != 0:
            z = int(z)
            cont[target_id].update({"amount": z})
        w = input("Insert a new type(in/out) (leave blank to keep original value):")
        if len(w) != 0:
            cont[target_id].update({"type": w})

# 测试用代码，不需要可直接删除
print("Current transaction records: ", cont)

核心改动说明 #

• 进入更新逻辑后先采集目标交易ID，先判断ID是否在存储交易的cont字典中，不存在直接返回提示避免运行报错
• 将原逻辑中固定使用最后一次录入的tranz变量替换为用户输入的target_id，实现精准修改指定ID的交易记录
• 优化输入提示，标注留空可保留原有值，使用体验更友好

内容的提问来源于stack exchange，提问作者Morph3us