title: How to read Python array from file?
body: <p>I would like to write and read Python array from a txt file. I know to how to write it, but reading the array requires me to provide an argument about the length of the array. I do not the length of the array in advance, is there a way to read the array without computing its length. My work in progress code below. If I provide 1 as the second argument in a.fromfile, it reads the first element of the array, I would like all elements to read (basically the array to be recreated).</p>
  
  <pre><code>from __future__ import division
  from array import array
  
  L = [1,2,3,4]
  indexes = array('I', L)
  
  with open('indexes.txt', 'w') as fileW:
      indexes.tofile(fileW)
  
  a = array('I', [])
  with open('indexes.txt', 'r') as fileR:
      a.fromfile(fileR,1)
  </code></pre>