title: Pandas: Find cell index: case insensitive
body: <p>I have a function that looks for a value in a panda dataframe using the 'isin' builtin function. The problem is that I would like to make this function case insensitive. I could parse every column to a serie and use the 'str.contains' but I find it a little ugly. Would you know a nice way to do this?</p>
  
  <p>Here is the function returning the index and col of a given world:</p>
  
  <pre><code>  def find_pos(self, titres):
      bool_table = self.document.isin(titres)
      for i in range(bool_table.shape[0]):
          for j in range(bool_table.shape[1]):
              boolean = bool_table.iloc[i][j]
              if boolean:
                  return i, j
  
      print(titres, " not found in csv", file=sys.stderr)
      return -1, -1
  </code></pre>
  
  <p>A working solution is to use lambdas:</p>
  
  <pre><code>bool_table = self.document.apply(lambda x: x.astype(str).str.lower()).isin([x.lower() for x in titres])
  </code></pre>
  
  <p>As I am new to python, maybe this isn't the nicest way to do this?</p>