title: Python: how to do basic data manipulation like in R?
body: <p>I have been working with R for several years. R is very strong in data manipulation. I'm learning python and I would like to know how to manipulate data using python. Basically my data sets are organized as data frames (e.g excel sheet). I would like to know (by example) how this kind of basic data manipulation task can be done using python?</p>
  
  <pre><code>1. Read csv file like the following
  
  var1, var2, var3
  1, 2, 3
  4, 5, 6 
  7, 8, 9
  
  2. Subset data where var2 in ('5', '8') 
  3. Make a new variable --&gt; var4 = var3 * 3
  4. Transpose this data
  5. Write to csv file
  </code></pre>
  
  <p>Your help and example is most appreciated! </p>