在panda的dataframe中选择头部为整数的列

Question

我在pandas中有一个数据框，看起来像这样：

   100  200  300  400
0    1    1    0    1
1    1    1    1    0

我要做的是从这个数据框中选择特定的列。但当我尝试以下代码时（df_矩阵是顶部显示的数据帧）：

^{pr2}$

它不起作用，从我能看出的是因为它是一个整数。我试着用str（100）来强迫它，但还是犯了同样的错误：

File "pandas\_libs\hashtable_class_helper.pxi", line 958, in pandas._libs.hashtable.Int64HashTable.get_item
TypeError: an integer is required

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "A:\python project\venv\lib\site-packages\pandas\core\indexes\base.py", line 3078, in get_loc
    return self._engine.get_loc(key)
  File "pandas\_libs\index.pyx", line 140, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 164, in pandas._libs.index.IndexEngine.get_loc
KeyError: '100'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "pandas\_libs\index.pyx", line 162, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 958, in pandas._libs.hashtable.Int64HashTable.get_item
TypeError: an integer is required

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "A:/python project/testing/testing4.py", line 42, in <module>
    intermediary_df = df_matrix["100"]
  File "A:\python project\venv\lib\site-packages\pandas\core\frame.py", line 2688, in __getitem__
    return self._getitem_column(key)
  File "A:\python project\venv\lib\site-packages\pandas\core\frame.py", line 2695, in _getitem_column
    return self._get_item_cache(key)
  File "A:\python project\venv\lib\site-packages\pandas\core\generic.py", line 2489, in _get_item_cache
    values = self._data.get(item)
  File "A:\python project\venv\lib\site-packages\pandas\core\internals.py", line 4115, in get
    loc = self.items.get_loc(item)
  File "A:\python project\venv\lib\site-packages\pandas\core\indexes\base.py", line 3080, in get_loc
    return self._engine.get_loc(self._maybe_cast_indexer(key))
  File "pandas\_libs\index.pyx", line 140, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 164, in pandas._libs.index.IndexEngine.get_loc
KeyError: '100'

有人知道怎么避开这个吗？谢谢！在

编辑1:

在尝试使用intermediary_df = df_matrix[100]后，它如期工作。顺便说一句，如果其他人面临此问题，并且希望同时选择多个列，您可以使用：

intermediary_df = df_matrix[[100, 300]]

输出将是：

   100  300
0    1    0
1    1    1

Answer 1

在本例中，只需使用下面的内容，因为您的列是int。在

intermediary_df = df_matrix[100]`

如果要将列作为str访问，请使用：

df.columns = [str(x) for x in df.columns]

然后呢

df['100']

输出

^{pr2}$

Answer 2

我想你的列类型是整数， 但如果不使用DataFrame.loc尝试此操作

示例：

intermediary_df = df_matrix.loc[:,100]

或者

^{pr2}$