title: Index must be called with a collection of some kind: assign column name to dataframe
body: <p>I have <code>reweightTarget</code> as follows and I want to convert it to a pandas Dataframe. However, I got following error:</p>
  
  <blockquote>
    <p>TypeError: Index(...) must be called with a collection of some kind,
    't' was passed</p>
  </blockquote>
  
  <p>If I remove <code>columns='t'</code>, it works fine. Can anyone please explain what's going on?</p>
  
  <pre><code>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)
  &lt;ipython-input-334-bf438351aaf2&gt; in &lt;module&gt;()
  ----&gt; 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,
  --&gt; 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 
  --&gt; 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:
  --&gt; 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 
  -&gt; 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):
  --&gt; 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__,
  --&gt; 483                                                       repr(data)))
      484 
      485     @classmethod
  
  TypeError: Index(...) must be called with a collection of some kind, 't' was passed
  </code></pre>