title: Python - Delete lines from dataframe (pandas)
body: <p>I am trying to delete certain information from a data frame, but the 'delete-command' (.drop) does not work like it should anyone got an idea?</p>
  <p>My Code:</p>
  <pre><code>    import pandas as pd
  
  def join():
  
      open_momox_xlsx = &quot;momox_ergebnisse.xlsx&quot;
      open_rebuy_xlsx = &quot;rebuy_ergebnisse.xlsx&quot;
  
      rebuy_xlsx = pd.read_excel(open_rebuy_xlsx)
      momox_xlsx = pd.read_excel(open_momox_xlsx)
  
      rebuy_data = rebuy_xlsx[['ReBuy']]
      isbn_data = rebuy_xlsx[['ISBN']]
      momox_data = momox_xlsx[['Momox']]
  
      dataframe = pd.DataFrame =({'ISBN': isbn_data, 'Rebuy': rebuy_data, 'Momox': momox_data})
      data = pd.concat(dataframe,axis=1, ignore_index=True)
  
      c=0
      #print(data[0])
      while c &lt; len(data):
  
          if data[1][c] and data[2][c] == '///':
              data.drop(index=c)
          elif data[1][c] and data[2][c] &lt; '1':
              data.drop(index=c)
          elif data[1][c] or data[2][c] &lt; '1' and data[1][c] or data[2][c] == '///' :
              data.drop(index=c)
          c=c+1
      print(data)
  </code></pre>
  <p>Output:</p>
  <pre><code>                0      1      2
  0   9783630876672  12,35   2.62
  1   9783423282789  11,67   6.07
  2   9783833879500  17,25  12.40
  3   9783898798822   6,91   1.16
  4   9783453281417  12,93   2.84
  5   9783630876672  12,35   4.08
  6   9783423282789  11,67   6.07
  7   9783833879500  17,25   9.94
  8   9783898798822   6,91   2.96
  9   9783453281417  12,93   2.68
  10     3927905909    ///    ///
  11     3872948210    ///   0.15
  12  9783293003781    ///   0.15
  13  9783423246842    ///    ///
  14  9783423247146    ///    ///
  15  9783423246934    ///    ///
  16     387294116x    ///    ///
  17  9783935597456   0,16   0.15
  18  9783423204545    ///    ///
  </code></pre>
  <p>Wanted Output:</p>
  <pre><code>                0      1      2
  0   9783630876672  12,35   2.62
  1   9783423282789  11,67   6.07
  2   9783833879500  17,25  12.40
  3   9783898798822   6,91   1.16
  4   9783453281417  12,93   2.84
  5   9783630876672  12,35   4.08
  6   9783423282789  11,67   6.07
  7   9783833879500  17,25   9.94
  8   9783898798822   6,91   2.96
  9   9783453281417  12,93   2.68
  </code></pre>
  <p>the if-statement seems to work properly, but the data.drop does not do what it should..</p>