title: Python libraries to generate charts and save as image file
body: <p>I require to generate bar charts and then save them as images, in .png or .bmp format.
  Can anyone please point me to such libraries.</p>
  
  <p>My basic need is to generate bar charts in an excel report.</p>
  
  <p>I thought of generating bar charts from any chart library as image files and then insert them into the excel report i am generating using xlwt library.</p>
  
  <p>Please let me know if there is a better way to achieve this objective.</p>
  
  <p>** I had read about pygooglechart module, but i think we need internet connection to generate charts and then download them. Please correct me if i am wrong about this.</p>