Package name normalization#

Project names are “normalized” for use in various contexts. This document describes how project names should be normalized.

Valid non-normalized names#

A valid name consists only of ASCII letters and numbers, period, underscore and hyphen. It must start and end with a letter or number. This means that valid project names are limited to those which match the following regex (run with re.IGNORECASE):



The name should be lowercased with all runs of the characters ., -, or _ replaced with a single - character. This can be implemented in Python with the re module:

import re

def normalize(name):
    return re.sub(r"[-_.]+", "-", name).lower()

This means that the following names are all equivalent:

  • friendly-bard (normalized form)

  • Friendly-Bard


  • friendly.bard

  • friendly_bard

  • friendly--bard

  • FrIeNdLy-._.-bArD (a terrible way to write a name, but it is valid)