title: Split one dataframe to multiple sub-dataframes based on common columns in Pandas
body: <p>Assuming the dataframe <code>df</code> as follows:</p>
  <pre><code>            ISIN  Coupon  Issue Date Maturity Date  Jan 18th  Jan 19th  \
  0   CA135087A610  0.0150   7/30/2012      6/1/2023    103.13    103.14   
  1   CA135087F254  0.0075  10/19/2015      3/1/2021    100.08    100.08   
  2   CA135087F585  0.0075   4/11/2016      9/1/2021    100.40    100.40   
  3   CA135087G328  0.0050  10/11/2016      3/1/2022    100.44    100.43   
  4   CA135087H490  0.0175   10/6/2017      3/1/2023    103.29    130.29   
  5   CA135087ZU15  0.0275    8/2/2011      6/1/2022    103.61    103.60   
  6   CA135087J546  0.0225   10/5/2018      3/1/2024    106.21    106.21   
  7   CA135087J967  0.0150    4/5/2019      9/1/2024    104.27    104.28   
  8   CA135087K528  0.0125  10/11/2019      3/1/2025    103.60    103.60   
  9   CA135087K940  0.0050    4/3/2020      9/1/2025    100.33    100.32   
  10  CA135087L518  0.0025   10/9/2020      3/1/2026     98.78     98.77   
  
      Jan 20th  
  0     103.10  
  1     100.08  
  2     100.39  
  3     100.41  
  4     103.25  
  5     103.57  
  6     106.17  
  7     104.25  
  8     103.59  
  9     100.30  
  10     98.76  
  </code></pre>
  <p>I need to split it into 3 sub-dataframes based on common columns <code>ISIN</code>, <code>Coupon</code>, <code>Issue Date</code>, <code>Maturity Date</code>.</p>
  <pre><code>common_columns = ['ISIN', 'Coupon', 'Issue Date', 'Maturity Date']
  df1.columns = common_columns + 'Jan 18th'
  df2.columns = common_columns + 'Jan 19th'
  df3.columns = common_columns + 'Jan 20th'
  </code></pre>
  <p>Then save them to an excel file, with sheet_name <code>Jan 18th</code>, <code>Jan 19th</code> and <code>Jan 20th</code>. Please note that in real data there are other date columns <code>Jan 21th</code>, <code>Jan 22th</code>, etc.</p>
  <p>To save the dataframes:</p>
  <pre><code>writer = pd.ExcelWriter('data.xlsx')
  df1.to_excel(writer, 'Jan 18th')
  df2.to_excel(writer, 'Jan 19th')
  df3.to_excel(writer, 'Jan 20th')
  writer.save()
  </code></pre>
  <p>How could I do that in Python? Thanks.</p>
  <p><strong>Update:</strong></p>
  <p>For first sheet's <code>ISIN</code> replaced by <code>2021-01-18</code>, Jan 18th by <code>Close Price</code>, second sheet's <code>ISIN</code> replaced by <code>2021-01-19</code>, Jan 19th by <code>Close Price</code>, third sheet's <code>ISIN</code> replaced by <code>2021-01-20</code>, Jan 20th by <code>Close Price</code>.</p>