动态（动态）构建字典时Python的“键错误”

我在这行代码上得到了错误-

result_dict['strat'][k]['name'] = current_comps[0].strip()
The error is : Keyerror: 'strat'

我有一条输入线

PERSON1 @@ CAR1 # ENTRY : 0 | EXIT : 0 @@ CAR2 # M1 : YES : 10/01/17 02:00 | M2 : NO : 10/02/16 03:00 | M3 : NO : 05/07/17 11:00 | M4 : YES : 01/01/16 03:00 @@ TRUCK # M3 : NO : 03/01/17 03:45 | M23 : NO : 01/01/14 07:00 | M27 : YES : 02/006/18 23:00

我希望解析这个输入以生成下面详细介绍的输出。作为这项工作的一部分，我正在尝试构建一个动态插入键和值的字典。我做这件事有很多问题

我能在这方面请求帮助吗

这是我到目前为止试过的-

# File read
f = open('input_data', 'r')
file_cont = f.read().splitlines()
f.close()

#json template

# Initialize dictionary
result_arr = []
result_dict = {}
k = 0

for item in file_cont:
    strat = item.split('@@')
    result_dict['Person'] = strat[0].strip()
    j = 1
    while j < len(strat):
        # Split various components of the main line
        current_comps = strat[j].split('#')

        # Name of strat being parsed
        result_dict['strat'][k]['name'] = current_comps[0].strip()

        # tfs across the various time frames
        tfs = current_comps[1].split('|')

        # First travel mode
        if current_comps[0].strip() == 'CAR1':
            temp_low_arr = tfs[0].split(':')
            temp_high_arr = tfs[1].split(':')
            result_dict['strat'][k]['Entry'] = temp_low_arr[1].strip()
            result_dict['strat'][k]['Exit'] = temp_high_arr[1].strip()

        # Second travel mode
        elif current_comps[0].strip() == 'CAR2':
            z = 0
            while z < len(tfs):
                # Split components of the sign
                sign_comp_car_2 = tfs[z].split(':')
                result_dict['strat'][k]['tf'][z]['path'] = sign_comp_ma_cross[0].strip()
                result_dict['strat'][k]['tf'][z]['sign'] = sign_comp_ma_cross[1].strip()
                result_dict['strat'][k]['tf'][z]['sign_time'] = sign_comp_ma_cross[2].strip()
                z += 1

        # Third travel mode
        elif current_comps[0].strip() == 'CAR3':
            b = 0
            while b < len(tfs):
                # Split components of the sign
                sign_car_3 = tfs[z].split(':')
                result_dict['strat'][k]['tf'][b]['path'] = sign_all_term[0].strip()
                result_dict['strat'][k]['tf'][b]['sign'] = sign_all_term[1].strip()
                result_dict['strat'][k]['tf'][b]['sign_time'] = sign_all_term[2].strip()
                b += 1
    j += 1
k += 1

---

问题在于，当result_dict['strat'][k]尚未初始化时，尝试在result_dict['strat'][k]中分配['name']字段。在运行for循环之前，字典没有名为strat的键。 现在，您可以执行类似于result_dict['strat']=dict的操作，将对象分配给dict中的该键，但当您使用result_dict['strat'][k]进一步为其下标时，它将首先尝试通过访问result_dict['strat']来解决该问题，并期望得到一个可下标的集合或一个字典作为回报。但是，由于该键还不存在，它会抛出错误

您可以改为初始化默认字典：

从集合导入defaultdict ... resultdict=defaultdict ... 否则，在现有代码中，您可以在进入循环之前在result_dict中初始化dict。

result_dict是什么？您的j和k增量与它们各自的最外层循环对齐。你确定你没有缺少一级缩进吗？

[{  
   "Person":"",
   "Transport":[  
      {  
         "Name":"CAR1",
         "Entry":"0",
         "Exit":"0"
      },
      {  
         "name":"CAR2:",
         "tf":[  
            {  
               "path":"M1",
               "sign":"YES",
               "sign_time":"10/01/17 02:00"
            },
            {  
               "path":"M2",
               "sign":"NO",
               "sign_time":"10/02/16 03:00"
            },
            {  
               "path":"M3",
               "sign":"NO",
               "sign_time":"05/07/17 11:00"
            },
            {  
               "path":"M4",
               "sign":"YES",
               "sign_time":"01/01/16 03:00"
            }
         ]
      },
      {  
         "name":"CAR3",
         "tf":[  
            {  
               "path":"M3",
               "sign":"NO",
               "sign_time":"03/01/17 03:45"
            },
            {  
               "path":"M23",
               "sign":"NO",
               "sign_time":"01/01/14 07:00"
            },
            {  
               "path":"M27",
               "sign":"Yes",
               "sign_time":"02/006/18 23:00"
            }
         ]
      }
   ]
}]