python - Pandas read_csv 无法正确加载逗号分隔的 CSV

Question

现在，我分析一下Kaggel的泰坦尼克号挑战。我的代码是这样的:

但我理想的输出是:

所以，在我最后的代码中是

df["Age"].fillna(df.Age.median(), inplace=True)

错误发生

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
/Users/XXXi/anaconda/envs/py36/lib/python3.6/site-packages/pandas/indexes/base.py in get_loc(self, key, method, tolerance)
   2133             try:
-> 2134                 return self._engine.get_loc(key)
   2135             except KeyError:

pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4433)()

pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4279)()

pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13742)()

pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13696)()

KeyError: 'Age'

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
<ipython-input-4-9763f0a9951c> in <module>()
----> 1 df["Age"].fillna(df.Age.median(), inplace=True)

/Users/XXXi/anaconda/envs/py36/lib/python3.6/site-packages/pandas/core/frame.py in __getitem__(self, key)
   2057             return self._getitem_multilevel(key)
   2058         else:
-> 2059             return self._getitem_column(key)
   2060 
   2061     def _getitem_column(self, key):

/Users/XXXi/anaconda/envs/py36/lib/python3.6/site-packages/pandas/core/frame.py in _getitem_column(self, key)
   2064         # get column
   2065         if self.columns.is_unique:
-> 2066             return self._get_item_cache(key)
   2067 
   2068         # duplicate columns & possible reduce dimensionality

/Users/XXXi/anaconda/envs/py36/lib/python3.6/site-packages/pandas/core/generic.py in _get_item_cache(self, item)
  1384         res = cache.get(item)
   1385         if res is None:
-> 1386             values = self._data.get(item)
   1387             res = self._box_item_values(item, values)
   1388             cache[item] = res

/Users/XXXi/anaconda/envs/py36/lib/python3.6/site-packages/pandas/core/internals.py in get(self, item, fastpath)
   3541 
   3542             if not isnull(item):
-> 3543                 loc = self.items.get_loc(item)
   3544             else:
   3545                 indexer = np.arange(len(self.items))[isnull(self.items)]

/Users/XXXi/anaconda/envs/py36/lib/python3.6/site-packages/pandas/indexes/base.py in get_loc(self, key, method, tolerance)
   2134                 return self._engine.get_loc(key)
   2135             except KeyError:
-> 2136                 return self._engine.get_loc(self._maybe_cast_indexer(key))
   2137 
   2138         indexer = self.get_indexer([key], method=method, tolerance=tolerance)

pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4433)()

pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4279)()

pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13742)()

pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13696)()

KeyError: 'Age'

我使用 sep=',' 所以我真的不明白为什么这段代码不能用逗号分隔。我该如何解决这个问题？

我跟着一个答案，但是错误发生了(我不知道为什么)

我的数据是

Answer 1

注意!

主要问题是下载数据。如果您在加载和处理 Kaggle Titanic 数据集时遇到问题，您可以从 here 重新下载 CSV。并重新运行您的程序。

---

可以通过delimiter=',':

df = pd.read_csv("Desktop/data/train.csv", delimiter=',')
print(df.head())

   PassengerId  Survived  Pclass  \
0            1         0       3   
1            2         1       1   
2            3         1       3   
3            4         1       1   
4            5         0       3   

                                                Name     Sex   Age  SibSp  \
0                            Braund, Mr. Owen Harris    male  22.0      1   
1  Cumings, Mrs. John Bradley (Florence Briggs Th...  female  38.0      1   
2                             Heikkinen, Miss. Laina  female  26.0      0   
3       Futrelle, Mrs. Jacques Heath (Lily May Peel)  female  35.0      1   
4                           Allen, Mr. William Henry    male  35.0      0   

   Parch            Ticket     Fare Cabin Embarked  
0      0         A/5 21171   7.2500   NaN        S  
1      0          PC 17599  71.2833   C85        C  
2      0  STON/O2. 3101282   7.9250   NaN        S  
3      0            113803  53.1000  C123        S  
4      0            373450   8.0500   NaN        S  


print(df.columns)

Index(['PassengerId', 'Survived', 'Pclass', 'Name', 'Sex', 'Age', 'SibSp',
       'Parch', 'Ticket', 'Fare', 'Cabin', 'Embarked'],
      dtype='object')

接下来，您可以创建各种映射:

mapping = {'male' : 0, 'female' : 1}

然后您将调用 pd.Series.replace:

df.Sex = df.Sex.replace(mapping)
print(df.Sex)

0    0
1    1
2    1
3    1
4    0
Name: Sex, dtype: int64