title: Openpyxl won't save file
body: <p>For some reason Openpyxl won't save the the xlsx file at the end of the program.
  I am trying to read measurments from a file, each line is a different measurement. I want to take them and write them  to excel as to make using this data later on easier. Everything seems to work, but in the end the data isn't saved, if i create new file where the changes should be saved it will not be created.</p>
  
  <pre><code>from openpyxl import load_workbook
  from openpyxl import Workbook
  wb = load_workbook(filename='Data_Base.xlsx')
  sheet = wb.worksheets[0]
  BS = []
  Signal = []
  with open('WifiData2.txt') as f:
   for line in f:
      y = int(line.split('|')[0].split(';')[3])
      x = int(line.split('|')[0].split(';')[2])
      floor = int(x = line.split('|')[0].split(';')[1])
      data = line.split("|")[1].strip()
      measurements = data.split(";")
      for l in measurements:
          raw = l.split(" ")
          BSSID = raw[0]
          signal_strength = raw[1]
          print(signal_strength)
          BS.append(BSSID)
          Signal.append(signal_strength)
  
      for row_num in range(sheet.max_row):
          num = row_num
          if row_num &gt; 1:
              test_X = int(sheet.cell(row=row_num, column=4).value)
              test_Y = int(sheet.cell(row=row_num, column=3).value)
              test_floor = int(sheet.cell(row=row_num, column=2).value)
              if (test_X == x and test_Y == y and test_floor == floor):
                  nr = nr + 1
  
      if (nr &gt; 3):
          q = 1
  
      if (q == 0):
  
          sheet.cell(row=sheet.max_row+1, column = 2, value = floor)
          sheet.cell(row=sheet.max_row + 1, column=3, value=x)
          sheet.cell(row=sheet.max_row + 1, column=4, value=y)
          sheet.cell(row=sheet.max_row + 1, column=2, value=sheet.max_row)
          for element in BS:
              nr = 0
              for col in sheet.max_column:
                  if BS[element] == sheet.cell(row=1, column=col).value:
                      sheet.cell(row=sheet.max_row + 1, column=col, value=Signal[element])
                      nr = 1
              if (nr == 0):
                  sheet.cell(row=1, column=sheet.max_column+1, value=BS[element])
                  sheet.cell(row=sheet.max_row+1, column=sheet.max_column + 1, value=BS[element])
  
      Signal.clear()
      BS.clear()
  wb.save('Data_Base1.xlsx')
  </code></pre>
  
  <p>What is weird that if i save the workbook earlier it will create the file. Of course it doesnt really work for me since any changes that i want made won't be made. I had similar issue when i tried it with xlrd/wt/utils combo. Does any1 know where the problem is ? </p>