New submission from picomancer: Try the following in your favorite Python version:
import json json.loads(".5") On my Python (2.7.4 and 3.3.1 on Ubuntu Saucy Salamander), I get an exception. However, x = .5 is a valid Python number. With respect to the parsing of floats by the json module, the docs state: By default, this is equivalent to ``float(num_str)``. This statement does not match the behavior I have observed in every version of Python I have tried, and is still in the bleeding-edge (as of this writing) at http://hg.python.org/cpython/file/9283a9c5d0ce/Doc/library/json.rst I think it's clear that the following changes should definitely be implemented: (1) The docs and behavior should match (2) Whatever the desired behavior is, there is a unit test specifically for this corner case Of course, to implement (1), there are two routes: (1a) Leading decimal floats should be accepted by the json module; the behavior should be changed to match the docs. Supported by Postel's Law -- "be liberal in what [your program] accept[s]"), see http://en.wikipedia.org/wiki/Postel%27s_law and the slightly relaxed attitude toward standards compliance detailed in the json module documentation. (1b) Leading decimal floats should be rejected by the json module; the docs should be changed to match the behavior. This fits with a strict standards compliance worldview. I think (1a) is better. In my particular use case, I was manually writing a json file with several numerical parameters. The backtrace given by json.load(open("whatever.json", "r")) is uninformative and merely says "No JSON object could be decoded"; finding the token the parser considered to be malformed was fairly easy since there were only six or seven keys. It could have been much worse if I was making manual changes to a larger JSON file. ---------- components: Library (Lib) messages: 205080 nosy: picomancer priority: normal severity: normal status: open title: json module won't parse a float that starts with a decimal point type: behavior versions: Python 2.7, Python 3.3, Python 3.4, Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue19871> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com