title: jupyter NameError: name 'zz' is not defined
body: <p>I have a small problem
  assign a value to 2 sliders, works
  assign 2 values to strings, works see the values changes when moving the sliders
  assign these strings to plt.imshow, get a error.
  string qq works on the image, string zz gives the error.
  here is a piece off code where the problem occur:</p>
  <pre><code>   from ipywidgets import interact
  
     @interact(q=(.1, 10))
     def f(q=5):
         qq=(str(q)+'E3')
     @interact(z=(.1, 10))
     def f(z=2):
         zz=(str(z)+'E3')
  
     plt.figure()
     plt.imshow(image_data, cmap='gray', vmin=zz, vmax=qq)
  </code></pre>
  <hr />
  <pre><code>Input In [52], in &lt;cell line: 16&gt;()
       11     zz=(str(z)+'E3')
       15 plt.figure()
  ---&gt; 16 plt.imshow(image_data, cmap='gray', vmin=zz, vmax=qq)
  
  NameError: name 'zz' is not defined
  </code></pre>
  <hr />
  <p>thanks.</p>
  <p>Willie.</p>