title: Can't append numpy arrays after for loop?
body: <p>After a for loop, I can not append each iteration into a single array:</p>
  
  <p>in:</p>
  
  <pre><code>for a in l:
  arr = np.asarray(a_lis)
  print(arr)
  </code></pre>
  
  <p>How can I append and return in a single array the above three arrays?:</p>
  
  <pre><code>   [[ 0.55133  0.58122  0.66129032  0.67562724  0.69354839  0.70609319
        0.6702509   0.63799283  0.61827957  0.6155914   0.60842294  0.60215054
        0.59946237  0.625448  0.60215054  0.60304659  0.59856631  0.59677419
        0.59408602  0.61021505]
      [ 0.58691756  0.6784946  0.64964158  0.66397849  0.67114695  0.66935484
        0.67293907  0.66845878  0.65143369  0.640681    0.63530466  0.6344086
        0.6281362   0.6281362   0.62634409  0.6281362   0.62903226  0.63799283
        0.63709677  0.6978495]
      [ 0.505018  0.53405018  0.59408602  0.65143369  0.66577061  0.66487455
        0.65412186  0.64964158  0.64157706  0.63082437  0.62634409  0.6218638
        0.62007168  0.6648746  0.62096774  0.62007168  0.62096774  0.62007168
        0.62275986  0.81362 ]]
  </code></pre>
  
  <p>I tried to append as a list, using numpy's append, merge, and hstack. None of them worked. Any idea of how to get the previous output?</p>