title: Import multiple sheets from excel spreadsheet into r
body: <p>I want to import multiple sheets, selected by a common string in the sheet name, from a single .xlsx file and concatenate them into single data frame. For example, if I have an excel file ('data.xlsx') with worksheets named samples1, samples2, samples3, controls1, controls2, controls3. I want to make a list of the worksheet names, such as:</p>
  
  <pre><code>sheet_list &lt;- lapply(excel_sheets('data.xlsx'), read_excel, path = 'data.xlsx')
  </code></pre>
  
  <p>Then, I want to import all sheets that contain 'samples' in the name and bind them into a data frame called 'samples'. How can I accomplish this efficiently?</p>