audio time-stretching?

[kj]

Does anyone know of a Python module for *moderate* "time-stretching"[1]
an MP3 (or AIFF) file?

FWIW, the audio I want to time-stretch is human speech.

TIA!

~K

[1] By "moderate time stretching" I mean, for example, taking an
audio that would normally play in 5 seconds, and stretch it so that
it plays in 7.5 seconds, keeping the pitch unchanged.  A lot of
software out there does this badly; e.g. the time-stretched audio
springs extraneous "beats" of intensity that are very obtrusive
and annoying; I guess it's some weird wave self-interference effect.
Also, I stress *moderate* time stretching to explicitly rule out
the extreme (~50X) time-stretching that software like PaulStretch
is designed to accomplish.