小编Dan*_*vic的帖子

我需要计算 pandas 数据框中唯一行的数量。我已经尝试过这个解决方案，但它会产生错误。

这是我的代码：

import pandas as pd

df = {'x1': ['A','B','A','A','B','A','A','A'], 'x2': [1,3,2,2,3,1,2,3]}
df = pd.DataFrame(df)

print df.groupby(['x1','x2'], as_index=False).count()

这是错误：

Traceback (most recent call last):
  File "/home/user/workspace/project/test.py", line 9, in <module>
    print df.groupby(['x1','x2'], as_index=False).count()
  File "/usr/local/lib/python2.7/dist-packages/pandas/core/groupby.py", line 4372, in count
    return self._wrap_agged_blocks(data.items, list(blk))
  File "/usr/local/lib/python2.7/dist-packages/pandas/core/groupby.py", line 4274, in _wrap_agged_blocks
    index = np.arange(blocks[0].values.shape[1])
IndexError: list index out of range

我究竟做错了什么？