title: the memory usage of my .csv file in pandas is bigger than my RAM. how is this possible?
body: <p>Please help me understand. I have 4 GB of RAM. I read in a full csv file that is 2.1GB large in pandas using</p>
  
  <pre><code>data = pd.read_csv('~/data.csv')
  </code></pre>
  
  <p>Now when I check the memory usage of the file with the following code:</p>
  
  <pre><code>data.memory_usage(deep=True).sum()
  </code></pre>
  
  <p>It returns 6012181982 bytes or 6GB. How is it possible that the memory usage is larger than my actual RAM and I won't get any memory errors?</p>