Python根据用户输入匹配多字典值报string indices must be integers错误如何解决

错误出在print(first_half[user_error])这行：first_half是从用户输入里截取的首字符字符串（比如输入"A1"时它是字符串"A"，不是你定义的字典变量A），字符串类型只能用整数作为索引取值，用字符串"A1"当索引自然会抛出"string indices must be integers"错误。

你需要额外建立首字符到对应字典的映射，通过首字符先拿到对应的目标字典，再从字典里取用户输入对应的值，修正后代码如下：

A = {
    "A1": "something1",
    "A2": "something2",
}
B = {
    "B1": "somethingelse1",
    "B2": "somethingelse2",
}
# 新增首字符到字典的映射
dict_map = {
    "A": A,
    "B": B
}
    
user_error = input("what is your error? ").upper()
first_half = user_error[0]
# 先通过首字符取到对应字典，再取用户输入对应的值
print(dict_map[first_half][user_error])

如果要兼容输入不存在的场景，避免程序直接报错，可以增加合法性判断：

A = {
    "A1": "something1",
    "A2": "something2",
}
B = {
    "B1": "somethingelse1",
    "B2": "somethingelse2",
}
dict_map = {
    "A": A,
    "B": B
}
    
user_error = input("what is your error? ").upper()
first_half = user_error[0]
if first_half in dict_map and user_error in dict_map[first_half]:
    print(dict_map[first_half][user_error])
else:
    print("未找到对应内容")

内容的提问来源于stack exchange，提问作者jadechessink