Currently PyPI accepts uploads for two distribution types: source distributions, and built distributions. PyPI accepts two built distribution types: wheels and eggs:

https://github.com/pypa/warehouse/blob/7732f2fb9eb0b1da032731d926a094f5f5d1488f/warehouse/forklift/legacy.py#L542

Eggs have never been widely used and have been far outpaced by wheels in recent years:

Some additional details:

• As of Dec 2021, eggs have accounted for less than 1% of built distribution uploads.
• pip deprecated the --egg command in 2016: Deprecate --egg pypa/pip#1749
• setuptools deprecated the bdist_egg command in Deprecated Eggsecutable Scripts pypa/setuptools#1764
• build only supports wheels for built distributions: https://pypa-build.readthedocs.io/en/latest/#python--m-build---wheel