# 12.7 `MimeWriter` -- Generic MIME file writer

This module defines the class `MimeWriter`. The `MimeWriter` class implements a basic formatter for creating MIME multi-part files. It doesn't seek around the output file nor does it use large amounts of buffer space. You must write the parts out in the order that they should occur in the final file. `MimeWriter` does buffer the headers you add, allowing you to rearrange their order.

`MimeWriter` (fp)
  Return a new instance of the `MimeWriter` class. The only argument passed, fp, is a file object to be used for writing. Note that a `StringIO` object could also be used.

- 12.7.1 MimeWriter Objects