python - 如何使用 pandas.diff 区分 int64

Question

>>> pd.DataFrame([3,4,5], dtype='int64').diff()
     0
0  NaN
1  1.0
2  1.0

我希望不要转换数据类型两次，这可能吗？

Answer 1

是的，如果您需要，您可以使用 np.diff -

numpy.diff(a, n=1, axis=-1)

Calculate the n-th discrete difference along given axis.

The first difference is given by out[n] = a[n+1] - a[n] along the given axis, higher differences are calculated by using diff recursively.

>>> df
   A  B
0  1  4
1  2  5
2  3  6

>>> np.diff(df.values, axis=0)
array([[1, 1],
       [1, 1]])

# or as in your example:
>>> np.diff(pd.DataFrame([3,4,5], dtype='int64')[0])
array([1, 1], dtype=int64)

请注意，如果不引入 NaN，则无法将其分配回原始数据帧，并且 NaN 是 float 类型，这意味着您的结果将自动强制为 float 。