title: Python pandas dataframe convert values without decimals
body: <p>In my dataframe, I have changed the NaN to 0 with the following code</p>
  
  <pre><code>df5.fillna(0, inplace=True)
  </code></pre>
  
  <p>However, I get the value "0.0" instead of "0". 
  I have >150 columns in this dataframe, some need the decimals, and the ones with converted NaN values must be without decimals. How can I get that. 
  My dataframe is for example as follows:</p>
  
  <pre><code>           genome  contig  genes    SCM  SCM/genes  TrfA_1__CP11611  \
  source                                                                
  20900_48    20900      48      1    0.0       0.00              NaN   
  20900_37    20900      37    130  103.0       0.79              Nan   
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>           genome  contig  genes    SCM  SCM/genes  TrfA_1__CP11611  \
  source                                                                
  20900_48    20900      48      1    0.0       0.00              0.0   
  20900_37    20900      37    130  103.0       0.79              0.0  
  </code></pre>
  
  <p>I need only "NaN" changed to "0" without affecting for example column SCM/genes. It is no option to use a code with columnnames, since I have >150 columns with NaN in this dataframe. </p>
  
  <p>Thanks</p>