zipencrypt is a Python module to provide weak password-based encryption for zipfiles. It is meant as a drop-in replacement for zipfile from the standard lib and provides the counterpart to the decryption implemented there.
It is implemented in pure python and does not rely on any 3rd party libraries.
Compatible to python 2.7 and 3.4+
pip install zipencrypt
from zipencrypt import ZipFile
with ZipFile("file.zip", mode="w") as f:
f.writestr("file1.txt", "plaintext", pwd=b"password")
The standard encryption of ZIP is known to be seriously flawed (see here). That is probably the reason why it is not implemented in zipfile in the standard lib. There are however legitimate use cases.