title: Reading multiple data files with a loop on Python
body: <p>Hi I have a over 200 data files with name similar names like abc.20.0000.catalog.out , abc.20.1000.catalog.out, abc.20.2000.catalog.out ...... abc.40.0000.catalog.out </p>
  
  <p>Each file contains data like this </p>
  
  <pre><code>   Group catalog for redshift  18.1000
   1) group ID
   2) group mass (Msun/h)
   3- 5) initial position (Mpc/h)
   6- 8) final position (Mpc/h)
   9-11) velocity (km/s)
   12) number of particles  
  
  250103187  0.227591E+08 1.86  1.03  2.51  1.65  1.06  2.53  -47.56  7.50  3.83    328
  202456030  0.167918E+08 0.29  4.57  2.02  0.23  4.63  2.14  -13.27  10.67 3.68    242
  89479147  0.763262E+06  1.47  4.80  0.89  1.34  4.83  0.99  -28.90  6.20  17.30    11 
  </code></pre>
  
  <p>each such file contains over 10^6 lines. </p>
  
  <p>I want to do the following:
  1. I want to read the data from each file and erase the text on top. 
  2. I want to then store the data from all these files into a single big list of   matrices, each matrix being the data from each of these files. </p>