title: Specify engine manually
body: <pre class="lang-py prettyprint-override"><code>for files in os.listdir(dir):
      if files[-4::] == 'xlsx':
          file_1 = pd.ExcelFile(os.path.join(dir,files))
          print('Path of File: ', os.path.join(dir,files))
          print('Student Number: ', pd.read_excel(file_1, sheet_name=0).iloc[0,1])
          for names in sheets_names:
              sheet = file_1.sheet_names.index(names)
              print('Sheet: ', file_1.sheet_names[sheet])
              file_original = pd.read_excel(file_1, sheet_name=sheet)
              file_copy = file_original.copy()
  </code></pre>
  <p>I have 13 excel files in a folder i want to read and write in ascending order (student number) . i have used following code but it shows error engine must give manually</p>