Comment 1 for bug 1396766

In the interest of transparency, the SDK doesn't support 100-Continue because neither requests nor urllib3 have the ability to support it. In order to support this, a user would probably have to subclass httplib.HTTPConnection and monkey-patch httplib.HTTPConnection before urllib3 imports it (and subsequently subclasses it). There is more information on the requests bug [1] related to this issue.

[1]: https://github.com/kennethreitz/requests/issues/713