#我的目标是从文件列表中把数据读取出来，按照timestamp作为对应，把ip做count并相加，用了这串代码以后，一种报错，是为什么？
#import pandas as pd
result = pd.DataFrame()
for item in file_list:
WIFI= pd.read_csv(item,index_col=None)
s = WIFI.groupby('Time')['ip'].count()
result = pd.concat([result, s], axis=0, ignore_index=True)
result
报错内容：
```python
KeyError Traceback (most recent call last)
Cell In[29], line 5
3 for item in file_list:
4 WIFI= pd.read_csv(item,index_col=None)
----> 5 s = WIFI.groupby('Time')['ip'].count()
6 result = pd.concat([result, s], axis=0, ignore_index=True)
7 result
File D:\ProgramData\Anaconda3\envs\ML_smart_infraustructure\lib\site-packages\pandas\core\frame.py:8399, in DataFrame.groupby(self, by, axis, level, as_index, sort, group_keys, squeeze, observed, dropna)
8396 raise TypeError("You have to supply one of 'by' and 'level'")
8397 axis = self._get_axis_number(axis)
-> 8399 return DataFrameGroupBy(
8400 obj=self,
8401 keys=by,
8402 axis=axis,
8403 level=level,
8404 as_index=as_index,
8405 sort=sort,
8406 group_keys=group_keys,
8407 squeeze=squeeze,
8408 observed=observed,
8409 dropna=dropna,
8410 )
File D:\ProgramData\Anaconda3\envs\ML_smart_infraustructure\lib\site-packages\pandas\core\groupby\groupby.py:959, in GroupBy.__init__(self, obj, keys, axis, level, grouper, exclusions, selection, as_index, sort, group_keys, squeeze, observed, mutated, dropna)
956 if grouper is None:
957 from pandas.core.groupby.grouper import get_grouper
--> 959 grouper, exclusions, obj = get_grouper(
960 obj,
961 keys,
962 axis=axis,
963 level=level,
964 sort=sort,
965 observed=observed,
966 mutated=self.mutated,
967 dropna=self.dropna,
968 )
970 self.obj = obj
971 self.axis = obj._get_axis_number(axis)
File D:\ProgramData\Anaconda3\envs\ML_smart_infraustructure\lib\site-packages\pandas\core\groupby\grouper.py:888, in get_grouper(obj, key, axis, level, sort, observed, mutated, validate, dropna)
886 in_axis, level, gpr = False, gpr, None
887 else:
--> 888 raise KeyError(gpr)
889 elif isinstance(gpr, Grouper) and gpr.key is not None:
890 # Add key to exclusions
891 exclusions.add(gpr.key)
KeyError: 'Time'
```
KeyError: 'Time'这是什么问题，怎么解决？
不知道你这个问题是否已经解决, 如果还没有解决的话: