Question

我想格式化一个numpy数组并将其保存在* .txt文件中

numpy数组如下所示：

a = [ 0.1   0.2   0.3   0.4   ... ] , [ 1.1   1.2   1.3   1.4   ... ] , ...

并且输出* .txt应如下所示：

0   1:0.1   2:0.2   3:0.3   4:0.4   ...
0   1:1.1   2:1.2   3:1.3   1:1.4   ...
...

不知道该怎么做。

谢谢。

好吧，jaba，谢谢你。我稍微修正了你的答案

import numpy as np

a = np.array([[1,3,5,6], [4,2,4,6], [6,3,2,6]])

ret = ""

for i in range(a.shape[0]):
    ret += "0 "
    for j in range(a.shape[1]):
        ret += " %s:%s" % (j+1,float(a[i,j])) #have a space between the numbers for better reading and i think it should starts with 1 not with 0 ?!
ret +="\n"

fd = open("output.sparse", "w")
fd.write(ret)
fd.close()

你觉得那样好吗？！

Answer 1

相当简单：

import numpy as np

a = np.array([[0.1, 0.2, 0.3, 0.4], [1.1, 1.2, 1.3, 1.4], [2.1, 2.2, 2.3, 2.4]])

with open("array.txt", 'w') as h:  
    for row in a:
        h.write("0")
        for n, col in enumerate(row):
            h.write("\t{0}:{1}".format(n+1, col))  # you can change the \t (tab) character to a number of spaces, if that's what you require
        h.write("\n")

输出：

0       1:0.1   2:0.2   3:0.3   4:0.4
0       1:1.1   2:1.2   3:1.3   4:1.4
0       1:2.1   2:2.2   3:2.3   4:2.4

我的原始示例涉及大量磁盘写入。如果您的阵列很大，这可能效率很低。但是，写入次数可以减少，例如：

with open("array.txt", 'w') as h:  
    for row in a:
        row_str = "0"
        for n, col in enumerate(row):
            row_str = "\t".join([row_str, "{0}:{1}".format(n+1, col)])
        h.write(''.join([row_str, '\n']))

您可以通过构造一个大字符串并将其写入结尾来将写入次数进一步减少到一个，但是在这将是真正有益的情况下（即一个巨大的数组），您会遇到内存问题从构建一个巨大的字符串。无论如何，它取决于你。

格式化numpy数组并保存为* .txt

1 个答案: