» ruby reopen +

In ruby we have a nifty reopen method we can use on references to file-handles that are already opened. This is helpful when you need to open a file as read-only, then you want to write to the same file, or you just want to use the same reference to point to a new file-handle. You simply reopen and go on about your merry way. Usually this is used within a File.open block. But with python you have to explicitly close the original file-handle and open a new one. So here is a convenience class-wrapper/method to emulate the ruby functionality:

class file(file):
  def reopen(self, name=None, mode='w', bufsize=None):
    if not name:
      name = self.name
    if not self.closed:
      self.close()
    if bufsize:
      self.__init__(name, mode, bufsize)
    else:
      self.__init__(name, mode)
    return self

fh = file('test.txt', 'rb')
print fh # <open file 'test.txt', mode 'rb' at 0xb7c92814>
fh.reopen(mode='wb')
print fh # <open file 'test.txt', mode 'wb' at 0xb7c92814>
fh.close()

This way we can reopen a different file, or the same file in a different mode, just as with ruby, and the custom method will take care of closing the existing file-handle, opening the new one, and keeping the same reference.