PyCryptodome is a self-contained Python package of low-level
cryptographic primitives.
It supports Python 2.7, Python 3.7 and newer, and PyPy.

The installation procedure depends on the package you want the library
to be in.

PyCryptodome is used here as an almost drop-in replacement for the old
PyCrypto library.
In this case, all modules are installed under the Crypto package.
One must avoid having both PyCrypto and PyCryptodome installed at the
same time, as they will interfere with each other.

For a library independent of the old PyCrypto, install PyCryptodomex.
In this case, all modules are installed under the Cryptodome package.
PyCrypto and PyCryptodome can coexist. There's another SlackBuild for
it in the repo.