## 12.2.12 Differences from `mimelib`

The `email` package was originally prototyped as a separate library called `mimelib`. Changes have been made so that method names are more consistent, and some methods or modules have either been added or removed. The semantics of some of the methods have also changed. For the most part, any functionality available in `mimelib` is still available in the `email` package, albeit often in a different way. Backward compatibility between the `mimelib` package and the `email` package was not a priority.

Here is a brief description of the differences between the `mimelib` and the `email` packages, along with hints on how to port your applications.

Of course, the most visible difference between the two packages is that the package name has been changed to `email`. In addition, the top-level package has the following differences:

- `messageFromString()` has been renamed to `message_from_string()`.

- `messageFromFile()` has been renamed to `message_from_file()`.

The `Message` class has the following differences:

- The method `asString()` was renamed to `as_string()`.

- The method `ismultipart()` was renamed to `is_multipart()`.

- The `get_payload()` method has grown a decode optional argument.

- The method `getall()` was renamed to `get_all()`.

- The method `addheader()` was renamed to `add_header()`.

- The method `gettype()` was renamed to `get_type()`.

- The method`getmaintype()` was renamed to `get_main_type()`.

- The method `getsubtype()` was renamed to `get_subtype()`.

- The method `getparams()` was renamed to `get_params()`. Also, whereas `getparams()` returned a list of strings, `get_params()` returns a list of 2-tuples, effectively the key/value pairs of the parameters, split on the "`=`" sign.

- The method `getparam()` was renamed to `get_param()`.

- The method `getcharsets()` was renamed to `get_charsets()`.

- The method `getfilename()` was renamed to `get_filename()`.

- The method `getboundary()` was renamed to `get_boundary()`.

- The method `setboundary()` was renamed to `set_boundary()`.

- The method `getdecodedpayload()` was removed. To get similar functionality, pass the value 1 to the decode flag of the get_payload() method.

- The method `getpayloadastext()` was removed. Similar functionality is supported by the `DecodedGenerator` class in the `email.Generator` module.

- The method `getbodyastext()` was removed. You can get similar functionality by creating an iterator with `typed_subpart_iterator()` in the `email.Iterators` module.

The `Parser` class has no differences in its public interface. It does have some additional smarts to recognize message/delivery-status type messages, which it represents as a `Message` instance containing separate `Message` subparts for each header block in the delivery status notification12.3.

The `Generator` class has no differences in its public interface. There is a new class in the `email.Generator` module though, called `DecodedGenerator` which provides most of the functionality previously available in the `Message.getpayloadastext()` method.

The following modules and classes have been changed:

- The `MIMEBase` class constructor arguments _major and _minor have changed to _maintype and _subtype respectively.

- The `Image` class/module has been renamed to `MIMEImage`. The _minor argument has been renamed to _subtype.

- The `Text` class/module has been renamed to `MIMEText`. The _minor argument has been renamed to _subtype.

- The `MessageRFC822` class/module has been renamed to `MIMEMessage`. Note that an earlier version of `mimelib` called this class/module `RFC822`, but that clashed with the Python standard library module `rfc822` on some case-insensitive file systems.

  Also, the `MIMEMessage` class now represents any kind of MIME message with main type message. It takes an optional argument _subtype which is used to set the MIME subtype. _subtype defaults to rfc822.

`mimelib` provided some utility functions in its `address` and `date` modules. All of these functions have been moved to the `email.Utils` module.

The `MsgReader` class/module has been removed. Its functionality is most closely supported in the `body_line_iterator()` function in the `email.Iterators` module.

#### Footnotes

... notification 12.3
  Delivery Status Notifications (DSN) are defined in RFC 1894.