title: Delete pandas group based on condition
body: <p>I have a pandas dataframe in with several groups and I would like to exclude groups where some conditions (in a specific column) are not met. E.g. delete here group B because they have a non-number value in column "crit1".</p>
  
  <p>I could delete specific columns based on the condition <code>df.loc[:, (df &gt;&lt; 0).any(axis=0)]</code> but then it doesn't delete the whole group. </p>
  
  <p>And somehow I can't make the next step and apply this to the whole group.</p>
  
  <pre><code>name    crit1   crit2
  A       0.3     4
  A       0.7     6
  B       inf     4
  B       0.4     3 
  </code></pre>
  
  <p>So the result after this filtering (allow only floats) should be:</p>
  
  <pre><code>A     0.3     4
  A     0.7     6
  </code></pre>