code: def clampfit_rename(path,char):
      
      assert len(char)==1 and type(char)==str, "replacement character must be a single character"
      assert os.path.exists(path), "path doesn't exist"
      files = sorted(os.listdir(path))
      files = [x for x in files if len(x)>18 and x[4]+x[7]+x[10]=='___']
      for fname in files:
          fname2 = list(fname)
          fname2[11]=char
          fname2="".join(fname2)
  
          if fname==fname2:
              print(fname, "==", fname2)
          else:
              print(fname, "->", fname2)
  #            fname=os.path.join(path,fname)
  #            fname2=os.path.join(path,fname2)
  #            if not os.path.exists(fname2):
  #                os.rename(fname,fname2)
      return
docs: Given ABFs and TIFs formatted long style, rename each of them to prefix their number with a different number.
  
      Example: 2017_10_11_0011.abf
      Becomes: 2017_10_11_?011.abf
      where ? can be any character.