title: How to read a file line by line with space separated values?
body: <p>I have a different kind of file format which contains millions of lines in a txt file.</p>
  <p>My file format is something like this:</p>
  <pre class="lang-none prettyprint-override"><code>12122.AA.K IRIR-93I3KD-OEPE-IE,6373,893939,09/12/2093,,N,EC,3838-38939-393
  12123.AA.K KKKS-93I3KD-OEPE-IE,9393,039033,09/12/2093,,N,EC,3838-38939-393
  12122.AA.K PEOEP-93I3KD-OEPE-IE,9033,930392,09/12/2093,,N,EC,3838-38939-393
  12124.AA.K MDJDK-93I3KD-OEPE-IE,3930,272882,09/12/2093,,N,EC,3838-38939-393
  12125.AA.K EOEPE-93I3KD-OEPE-IE,8393,039393,09/12/2093,,N,EC,3838-38939-393
  </code></pre>
  <p>In Python, I want to split each line into a key and a value:</p>
  <pre class="lang-none prettyprint-override"><code>Key: 12122.AA.K
  Value: IRIR-93I3KD-OEPE-IE,3833,343343,09/12/2093,,N,EC,3838-38939-393
  </code></pre>
  <p>As you can see, the key and value are differentiated by one empty space only.</p>
  <p>What's the efficient way of getting in python?</p>