获取“TypeError：float（）参数必须是一个字符串或数字”与熊猫的情节（）

Question

我正在通过简单的熊猫教程。而我试图绘制由dtype ='datetime64 [ns]'索引的DataFrame，但是，当我尝试绘图时，我假设matplotlib试图将日期转换为浮点数，这会引发异常。

>>> df.index 
DatetimeIndex(['2012-01-01', '2012-01-02', '2012-01-03', '2012-01-04', 
      '2012-01-05', '2012-01-06', '2012-01-07', '2012-01-08', 
      '2012-01-09', '2012-01-10', 
      ... 
      '2012-12-22', '2012-12-23', '2012-12-24', '2012-12-25', 
      '2012-12-26', '2012-12-27', '2012-12-28', '2012-12-29', 
      '2012-12-30', '2012-12-31'], 
      dtype='datetime64[ns]', name=u'Date', length=366, freq=None) 

>>> df.plot() 
Traceback (most recent call last): 
    ... 
    File "/usr/local/lib/python2.7/dist-packages/matplotlib/lines.py", line 676, in recache 
    x = np.asarray(xconv, np.float_) 
    File "/usr/local/lib/python2.7/dist-packages/numpy/core/numeric.py", line 531, in asarray 
    return array(a, dtype, copy=False, order=order) 
TypeError: float() argument must be a string or a number 

我在做什么错？

注：我下面很简单的教程在这里：http://nbviewer.jupyter.org/github/jvns/pandas-cookbook/blob/v0.1/cookbook/Chapter%201%20-%20Reading%20from%20a%20CSV.ipynb

Answer 1

的教程绘制号码colmn 2，而不是日期列1：

日期

2012-01-01

2012-01-02

2012-01-03

....

因此，你的情节失去了一些东西，再次检查您输入...