Python 必须使用某种集合调用索引：将列名分配给数据框
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Index must be called with a collection of some kind: assign column name to dataframe
提问by Lisa
I have reweightTargetas follows and I want to convert it to a pandas Dataframe. However, I got following error:
我有reweightTarget以下内容，我想将其转换为熊猫数据框。但是，我收到以下错误：
TypeError: Index(...) must be called with a collection of some kind, 't' was passed
TypeError: Index(...) 必须用某种集合调用，'t' 被传递
If I remove columns='t', it works fine. Can anyone please explain what's going on?
如果我删除columns='t'，它工作正常。谁能解释一下这是怎么回事？
reweightTarget
Trading dates
2004-01-31 4.35
2004-02-29 4.46
2004-03-31 4.44
2004-04-30 4.39
2004-05-31 4.50
2004-06-30 4.53
2004-07-31 4.63
2004-08-31 4.58
dtype: float64
pd.DataFrame(reweightTarget, columns='t')
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-334-bf438351aaf2> in <module>()
----> 1 pd.DataFrame(reweightTarget, columns='t')
C:\Anaconda3\lib\site-packages\pandas\core\frame.py in __init__(self, data, index, columns, dtype, copy)
253 else:
254 mgr = self._init_ndarray(data, index, columns, dtype=dtype,
--> 255 copy=copy)
256 elif isinstance(data, (list, types.GeneratorType)):
257 if isinstance(data, types.GeneratorType):
C:\Anaconda3\lib\site-packages\pandas\core\frame.py in _init_ndarray(self, values, index, columns, dtype, copy)
421 raise_with_traceback(e)
422
--> 423 index, columns = _get_axes(*values.shape)
424 values = values.T
425
C:\Anaconda3\lib\site-packages\pandas\core\frame.py in _get_axes(N, K, index, columns)
388 columns = _default_index(K)
389 else:
--> 390 columns = _ensure_index(columns)
391 return index, columns
392
C:\Anaconda3\lib\site-packages\pandas\indexes\base.py in _ensure_index(index_like, copy)
3407 index_like = copy(index_like)
3408
-> 3409 return Index(index_like)
3410
3411
C:\Anaconda3\lib\site-packages\pandas\indexes\base.py in __new__(cls, data, dtype, copy, name, fastpath, tupleize_cols, **kwargs)
266 **kwargs)
267 elif data is None or lib.isscalar(data):
--> 268 cls._scalar_data_error(data)
269 else:
270 if (tupleize_cols and isinstance(data, list) and data and
C:\Anaconda3\lib\site-packages\pandas\indexes\base.py in _scalar_data_error(cls, data)
481 raise TypeError('{0}(...) must be called with a collection of some '
482 'kind, {1} was passed'.format(cls.__name__,
--> 483 repr(data)))
484
485 @classmethod
TypeError: Index(...) must be called with a collection of some kind, 't' was passed
回答by Xyrus
Documentation: http://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.html
文档：http: //pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.html
columns : Index or array-like
Column labels to use for resulting frame. Will default to np.arange(n) if no column labels are provided
列：索引或类似数组
用于结果框架的列标签。如果没有提供列标签，将默认为 np.arange(n)
Example:
例子：
df3 = DataFrame(np.random.randn(10, 5), columns=['a', 'b', 'c', 'd', 'e'])
df3 = DataFrame(np.random.randn(10, 5), columns=['a', 'b', 'c', 'd', 'e'])
Try to use:
尝试使用：
pd.DataFrame(reweightTarget, columns=['t'])
回答by hamed baziyad
When you want to set an indexor columnsin data frame you should define it in listmood.
当您想在数据框中设置index或 时columns，您应该根据list心情定义它。
pd.DataFrame(reweightTarget, columns=list('t'))
