如何合并一个numpy数组和一个文本列并导出到csv


问题内容

我想结合一个numpy数组和一个列,该列是一个字符串,作为标识符导出到csv文件,然后可以将其导入到excel。

例如:

a=np.random.rand(6,4)
b=[]
for i in range(6):
  b.append('test')

所以现在我想将b附加到a的最后一列

完成后,我想使用np.savetxt(或类似文件)将数组写入文件。

任何帮助,不胜感激。


问题答案:
import numpy as np

a = np.random.rand(6,4)
b = ['test']*6

c = np.column_stack([a,b])
np.savetxt('/tmp/out', c, delimiter=',', fmt='%s')

写类似

0.70503807191,0.19298150889,0.962915679186,0.655430709887,test
0.586655200042,0.379720344068,0.136924270418,0.547277504174,test
0.777238053817,0.642467338742,0.709351872598,0.932239808362,test
0.386983024375,0.753005132745,0.124107902275,0.472997270033,test
0.169711196953,0.735713880779,0.280588048467,0.726851876957,test
0.20578446385,0.379406838045,0.640154333103,0.579077700263,test

/tmp/out


按照Paul的建议,如果您有pandas,则可以很容易地形成一个DataFrame,然后调用其to_csv方法:

import numpy as np
import pandas as pd

a = np.random.rand(6,4)
b = np.asarray(['test']*6)

df = pd.DataFrame(a)
df['b'] = b

df.to_csv('/tmp/out')