使用str.find()查找部分字符串，然后替换字典中的值

def replace_values(string, dictionary):
    start_index = string.find('{')
    while start_index != -1:
        end_index = string.find('}', start_index)
        if end_index != -1:
            key = string[start_index+1:end_index]
            if key in dictionary:
                string = string.replace('{' + key + '}', dictionary[key])
            start_index = string.find('{', end_index)
        else:
            break
    return string

# 示例用法
string = "Hello, {name}! Today is {day}."
dictionary = {'name': 'John', 'day': 'Monday'}
result = replace_values(string, dictionary)
print(result)

Hello, John! Today is Monday.