Problem

pprint.isreadable() returns True for float('inf'), float('-inf'), and float('nan'), but their repr() values are not valid Python literals — eval() raises NameError. The documented contract of isreadable is that the representation can be used to recreate the value via eval().

Reproducer

import pprint
print(pprint.isreadable(float('inf')))  # True — but eval('inf') raises NameError

Fix

In Lib/pprint.py, in _safe_repr, add a check for float specials and return readable=False for them.

• Issue: pprint.isreadable() returns True for float('inf'), float('-inf'), float('nan') #145117