title: Remove prefix (or suffix) substring from column headers in pandas
body: <p>I'm trying to remove the sub string _x that is located in the end of part of my df column names.</p>
  
  <p><strong>Sample df code:</strong></p>
  
  <pre><code>import pandas as pd
  
  d = {'W_x': ['abcde','abcde','abcde']}
  df = pd.DataFrame(data=d)
  
  df['First_x']=[0,0,0]
  df['Last_x']=[1,2,3]
  df['Slice']=['abFC=0.01#%sdadf','12fdak*4%FC=-0.035faf,dd43','FC=0.5fasff']
  </code></pre>
  
  <p><strong>output:</strong></p>
  
  <pre><code>     W_x  First_x Last_x                 Slice
  0  abcde      0     1                   abFC=0.01
  1  abcde      0     2  12fdak*4%FC=-0.035faf,dd43
  2  abcde      0     3                 FC=0.5fasff
  </code></pre>
  
  <p><strong>Desired output:</strong></p>
  
  <pre><code>       W  First  Last                       Slice
  0  abcde      0     1                   abFC=0.01
  1  abcde      0     2  12fdak*4%FC=-0.035faf,dd43
  2  abcde      0     3                 FC=0.5fasff
  </code></pre>