title: Insert variable values into a string
body: <p>I want to introduce a variable <code>[i]</code> into a string in Python.</p>
  <p>For example look at the following script. I just want to be able to give a name to the image, for example <code>geo[0].tif</code> ... to <code>geo[i].tif</code>, or if you use an accountant as I can replace a portion of the value chain to generate a counter.</p>
  <pre><code>data = self.cmd(&quot;r.out.gdal in=rdata out=geo.tif&quot;)
  self.dataOutTIF.setValue(&quot;geo.tif&quot;)
  </code></pre>