title: I am trying to fill all NaN values in rows with number data types to zero in pandas
body: <p>I have a DateFrame with a mixture of string, and float rows.  The float rows are all still whole numbers and were only changed to floats because their were missing values.  I want to fill in all the NaN rows that are numbers with zero while leaving the NaN in columns that are strings.  Here is what I have currently.</p>
  
  <pre><code>df.select_dtypes(include=['int', 'float']).fillna(0, inplace=True)
  </code></pre>
  
  <p>This doesn't work and I think it is because .select_dtypes() returns a view of the DataFrame so the .fillna() doesn't work.  Is there a method similar to this to fill all the NaNs on only the float rows.</p>