TypeError when trying to sort a string of a number and a string

Python 3.3 and Python 3.4 fail to sort collections that contain strings that are also numbers:

>>> import natsort
>>> natsort.natsorted(('a', '1'))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/kwpolska/virtualenvs/nikola-py3/lib/python3.4/site-packages/natsort/natsort.py", line 247, in natsorted
    return sorted(seq, key=lambda x: natsort_key(key(x),
TypeError: unorderable types: float() < str()

This works just fine in Python 2.7.6.

via getnikola/nikola#1275 (cc @devurandom)

[ralsina]

You can use key(). For example, you can always compare tuples. The behaviour of sorted() is to compare elements left-to-right, and decide on the first one that’s not equal. So, to compare floats and strings, you could compare (‘string’, ‘1’) to (‘float’, 2.0). You can even generate the first element by using type()

[fake-name]

I actually left it running for a while, and it made it to ~35 million items before I got bored and stopped it.

It doesn’t seem like it’s really worth bothering pull requesting for, just feel free to copy & paste it wherever.

I’m not sure how one would integrate a actual random-fuzzer into a unit-testing system. They’re kind of intrinsically non-repeatable, so they’re not guaranteed to catch issues. I guess you could set it up so it just runs a number of iterations. You would need some mechanism to log the string that triggers failure, though.