title: Add a text column to the dataframe based on characters in another column of the same dataframe
body: <p>The following is a small sample of my data frame:</p>
  
  <pre><code>&gt; print(df1)
          Section                     A                      B                      
  1   ./100-12-S00.xlsx           0.6032591              0.4554364
  2   ./108-15-S01.xlsx           0.7109148              0.5367121
  3   ./92-12-S00.xlsx            0.6032591              0.4554364
  4   ./124-9-S05.xlsx            0.7109148              0.5367121
  5   ./116-15-S11.xlsx           0.6032591              0.4554364
  6   ./108-9-S06.xlsx            0.7109148              0.5367121
  7   ./84-12-S08.xlsx            0.6032591              0.4554364
  8   ./124-15-S11.xlsx           0.7109148              0.5367121
  9   ./92-12-S00.xlsx            0.6032591              0.4554364
  10  ./116-15-S03.xlsx           0.7109148              0.5367121
  11  ./100-12-S02.xlsx           0.6032591              0.4554364
  12  ./84-9-S05.xlsx             0.7109148              0.5367121
  </code></pre>
  
  <p>I would like to add a new column of texts to df1 based on the characters in the Section column. This must be done such that if Section includes:</p>
  
  <pre><code>&gt; print(df2)
       Section    Names
  1    S00        Baseline
  2    S01        Sample1
  3    S02        Sample2
  4    S03        Sample3
  5    S04        Sample4
  6    S05        Sample5
  7    S06        Sample6
  8    S07        Sample7
  9    S08        Sample8
  10   S09        Sample9
  11   S10        Sample10
  12   S11        AASHTO
  </code></pre>
  
  <p>I want df1 to include a new column called Names based on what is in the Section column.</p>
  
  <p>The expected output is:</p>
  
  <pre><code>&gt; print(df3)
          Section                 A              B          Names                  
  1   ./100-12-S00.xlsx       0.6032591      0.4554364    Baseline
  2   ./108-15-S01.xlsx       0.7109148      0.5367121    Sample1
  3   ./92-12-S00.xlsx        0.6032591      0.4554364    Baseline
  4   ./124-9-S05.xlsx        0.7109148      0.5367121    Sample5
  5   ./116-15-S11.xlsx       0.6032591      0.4554364    AASHTO
  6   ./108-9-S06.xlsx        0.7109148      0.5367121    Sample6
  7   ./84-12-S08.xlsx        0.6032591      0.4554364    Sample8
  8   ./124-15-S11.xlsx       0.7109148      0.5367121    AASHTO
  9   ./92-12-S00.xlsx        0.6032591      0.4554364    Baseline
  10  ./116-15-S03.xlsx       0.7109148      0.5367121    Sample3
  11  ./100-12-S02.xlsx       0.6032591      0.4554364    Sample2
  12  ./84-9-S05.xlsx         0.7109148      0.5367121    Sample5
  </code></pre>