<a id="launchpadlib-api-compatibility"></a>

# launchpadlib API compatibility

#### IMPORTANT
This document has been migrated from help.launchpad.net as is, and has not
yet been revised. The content might be outdated, links and images could be
broken. We are aware and will fix any issues as soon as possible.

The API compatibility of the launchpadlib Python library has not always
been maintained as well as an author of a program using it would hope.

## &= 1.5.5 (&= Ubuntu Lucid Lynx)

Version 1.5.5 added the support for accessing various different versions
of the remote web-service API (at the time of writing, these versions are
known as “beta”, “1.0” and “devel”). Whilst the new version parameters were
compatibly added, there was an incompatible change to the URLs that launchpadlib
would accept as service_root parameters:

* launchpadlib 1.5.4 and earlier **requires** URLs of the form [https://api.launchpad.net/beta/](https://api.launchpad.net/beta/)
* launchpadlib 1.5.5 and later **requires** URLs of the form [https://api.launchpad.net/](https://api.launchpad.net/)

and either will break in non-obvious ways if you give it the wrong form.

## 1.8.0 (no Ubuntu release)

Version 1.8.0 changed things, which 1.9.0 then changed again.
And, it never went into any final Ubuntu release. Probably best to just pretend it doesn’t exist.

## &= 1.9.0 (&= Ubuntu Natty Narwhal)

Version 1.9.x’s changes versus 1.6.x include a major refactor of how
authentication tokens are obtained. Notable consequences:

* Different kinds of tokens are obtained, and they are stored differently by default (in GNOME keyring or similar technologies instead of files), meaning it’s highly unlikely that tokens stored by launchpadlib 1.6.x will be noticed by 1.9.x, so users will have to re-authorize.
* Most of the methods by which a Launchpad object is obtained have changed significantly:

#### NOTE
Positional parameter indices referred to below are 1-based.

### `Launchpad.init`

* Parameters authorization_engine and credential_store inserted at position 2.

#### CAUTION
It is no longer safe to call `Launchpad.__init__` with positional parameters beyond
the first in compatible applications!

### `Launchpad.login`

* Method is now deprecated.
* Five new parameters inserted at position 8. Mitigating factor: the only parameter
  after this was version, which was probably being passed as a keyword argument anyway.

### `Launchpad.get_token_and_login`

* Method is now deprecated.
* Parameter 6 renamed from `authorizer_class` to authorization_engine.
* Parameters `credential_store` and `credential_save_failed` inserted at position 9.
  Mitigating factor: the only parameter after this was version, which was probably
  being passed as a keyword argument anyway.

### `Launchpad.login_with`

* Positional parameter 1 changed from `consumer_name` to `application_name` to attempt to
  force common use-cases to acquire a desktop integration rather than consumer-specific token without code changes.
* Parameter 6 renamed from `authorizer_class` to `authorization_engine`.
* New parameter `consumer_name` appended to replace the incarnation removed at position 1.
  (But it does not actually work - see [https://launchpad.net/bugs/755313](https://launchpad.net/bugs/755313))
* New parameters `credential_save_failed` and `credential_store` appended.