Agreed, especially about simplejson. I work on a project that uses simplejson, and it leads to ugly type checking all over the place because you never know what

Agreed, especially about simplejson. I work on a project that uses simplejson, and it leads to ugly type checking all over the place because you never know what your JSON string got turned into. For example: https://github.com/openstack/swift/blob/39c1362a4f5a7df75730d3388bf37c3b5fbdc9c8/swift/account/reaper.py#L362 https://github.com/openstack/swift/blob/39c1362a4f5a7df75730... and https://github.com/openstack/swift/blob/39c1362a4f5a7df75730d3388bf37c3b5fbdc9c8/swift/common/db.py#L51 https://github.com/openstack/swift/blob/39c1362a4f5a7df75730... and https://github.com/openstack/swift/blob/39c1362a4f5a7df75730d3388bf37c3b5fbdc9c8/swift/common/middleware/slo.py#L291 https://github.com/openstack/swift/blob/39c1362a4f5a7df75730... and many more just like those. The worst part is the bugs that appear or disappear depending on whether simplejson's speedups module is in use or not.