title: numerical sort a column containing numbers and strings (pandas/python)
body: <p>I have to sort a data frame on column 1 and 2; column 1 contains numbers and text, which should first be numerically sorted. In excel this is the standard way to sort, but not in pandas..  I couldn't find much info on how to do this in the pandas manual.. </p>
  
  <p>So this dataframe: </p>
  
  <pre><code>Z   762320  296 1
  Z   861349  297 0
  1   865545  20  20
  1   865584  297 0
  22  865625  297 0
  2   865628  292 5
  10  865662  297 0
  1   865665  296 0
  11  865694  293 1
  1   865700  297 0
  10  866429  297 0
  11  866438  297 0
  </code></pre>
  
  <p>should be:</p>
  
  <pre><code>1   865545  20  20
  1   865584  297 0
  1   865665  296 0
  1   865700  297 0
  2   865628  292 5
  10  865662  297 0
  10  866429  297 0
  11  865694  293 1
  11  866438  297 0
  22  865625  297 0
  Z   762320  296 1
  Z   861349  297 0
  </code></pre>
  
  <p>when i do df.sort([0,1]) i get: </p>
  
  <pre><code>     0       1    2   3
  1    1  865545   20  20
  2    1  865584  297   0
  3    1  865665  296   0
  4    1  865700  297   0
  6   10  865662  297   0
  7   10  866429  297   0
  8   11  865694  293   1
  9   11  866438  297   0
  5    2  865628  292   5
  10  22  865625  297   0
  0    Z  762320  296   1
  11   Z  861349  297   0
  </code></pre>