的Python /大熊貓 - KeyError異常合併dataframes

我有兩個dataframes我試圖合併：的Python /大熊貓 - KeyError異常合併dataframes

target: 

    version city_id   code 
id                    
4   2  4 5736201000175 
26  2  3 8290265000183 
27  3  3 9529184000156 
30  3  3 9263064000150 
34  2  3 9312770000144 
54  1  3 8407830000140 
55  1  3 5590100000139 



city: 

    federation_unit_id  name 
id           
3     8 SAO PAULO 
4     8 CAMPINAS 
7     8 BARUERI 
8     8 BEBEDOURO 
9     8  SANTOS

我想將它們合併合併target的「city_id」與city的「ID」，在這樣，最終的數據幀是這樣的：

target: 

    version city_id   code federation_unit_id  name 
id                    
4   2  4 5736201000175      8 CAMPINAS 
26  2  3 8290265000183      8 SAO PAULO 
27  3  3 9529184000156      8 SAO PAULO 
30  3  3 9263064000150      8 SAO PAULO 
34  2  3 9312770000144      8 SAO PAULO 
54  1  3 8407830000140      8 SAO PAULO 
55  1  3 5590100000139      8 SAO PAULO

爲了實現這個目標，我想用下面的代碼：

target=target.merge(city, left_on='city_id', right_on='id')

但是它一直讓我以下KeyError異常：

Traceback (most recent call last): 
    File "/file.py", line 12, in <module> 
target=target.merge(city, left_on='index', right_on='city_id') 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/frame.py", line 4437, in merge 
copy=copy, indicator=indicator) 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tools/merge.py", line 38, in merge 
copy=copy, indicator=indicator) 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tools/merge.py", line 210, in __init__ 
self.join_names) = self._get_merge_keys() 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/tools/merge.py", line 434, in _get_merge_keys 
right_keys.append(right[rk]._values) 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/frame.py", line 1997, in __getitem__ 
return self._getitem_column(key) 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/frame.py", line 2004, in _getitem_column 
return self._get_item_cache(key) 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/generic.py", line 1350, in _get_item_cache 
values = self._data.get(item) 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/core/internals.py", line 3290, in get 
loc = self.items.get_loc(item) 
    File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pandas/indexes/base.py", line 1947, in get_loc 
return self._engine.get_loc(self._maybe_cast_indexer(key)) 
    File "pandas/index.pyx", line 137, in pandas.index.IndexEngine.get_loc (pandas/index.c:4154) 
    File "pandas/index.pyx", line 159, in pandas.index.IndexEngine.get_loc (pandas/index.c:4018) 
    File "pandas/hashtable.pyx", line 675, in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:12368) 
    File "pandas/hashtable.pyx", line 683, in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:12322) 
KeyError: 'id'

我無法找出什麼我做錯了：/ 能有人幫助？

來源

2017-07-23 abutremutante

中城市數據幀id似乎是一個指標，嘗試設置right_index=True：

target.merge(city, left_on='city_id', right_index=True)

來源

2017-07-23 20:21:56 Psidom

您可以使用join

join本質上是以指數爲導向的。但是，您可以在構成左側的數據框中指定要加入的替代列。如果我們在target上調用join方法，那麼我們想要指定'city_id'作爲替代列。 city數據幀已經有適當的索引。

來源

2017-07-23 20:25:31 piRSquared

的Python /大熊貓 - KeyError異常合併dataframes

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