title: Replace values in a pandas dataframe crashes the kernel
body: <p>I have a dataframe with 10 columns with integers:</p>
  
  <pre><code>site1 site2 site3 ... site10
  55    56    198 ...   340
  10    101   200 ...   900
  ...
  1     1090  500 ...   300
  </code></pre>
  
  <p>I have a dictionary to replace some of these values:</p>
  
  <pre><code>dict = { "55" : "198" .... }
  </code></pre>
  
  <p>when I do:</p>
  
  <p>df.replace(dict)</p>
  
  <p>my kaggle kernel crashes. the df has 350k rows. the dict has 15k</p>
  
  <p>I'm guessing it's too much for the kernel to process. How to do this without crashing the kernel?</p>
  
  <p>Thanks!</p>