python3-cysignals-pari - 1.10.2+ds-6 main

Since Cython optimizes for speed, Cython normally does not check
for interrupts. The cysignals package provides mechanisms to handle
interrupts (and other signals and errors) in Cython code.
.
This package installs the library for Python 3; this very library
was built against the PARI/GP library.