Nidy列表的1D阵列到2D阵列

I have a large list files that contain 2D numpy arrays pickled through numpy.save. I am trying to read the first column of each file and create a new 2D array.

我有一个大的列表文件，其中包含通过numpy.save pickled的2D numpy数组。我试图读取每个文件的第一列并创建一个新的2D数组。

I currently read each column using numpy.load with a mmap. The 1D arrays are now in a list.

我目前使用带有mmap的numpy.load读取每一列。 1D阵列现在位于列表中。

col_list = []
for f in file_list:
    Temp = np.load(f,mmap_mode='r')
    col_list.append(Temp[:,0])

How can I convert this into a 2D array?

如何将其转换为2D数组？

3 个解决方案

#1

You can just call np.array on the list of 1D arrays.

您只需在1D数组列表中调用np.array即可。

>>> import numpy as np
>>> arrs = [np.array([1,2,3]), np.array([4,5,6]), np.array([7,8,9])]
>>> arrs
[array([1, 2, 3]), array([4, 5, 6]), array([7, 8, 9])]
>>> arr2d = np.array(arrs)
>>> arr2d.shape
(3, 3)
>>> arr2d
array([[1, 2, 3],
       [4, 5, 6],
       [7, 8, 9]])

#2

The array may be recreated:

可以重新创建数组：

a = np.array(a.tolist())

#3

You can use

您可以使用

numpy.stack(arrays, axis=0)

if you have an array of arrays. You can specify the axis in case you want to stack columns and not rows.

如果你有一个数组数组。如果要堆叠列而不是行，可以指定轴。

#1