5 ms·

Show HN: Forbidden Fruit – Patch built-in Python objects

35 points by clarete 14y ago

herge 14y ago
Man, having this as a context manager (maybe with the help of contextlib) would be great, because context managers are great.
- clarete 14y ago
  That's the idea. Everything to make testing easier! :)
hcarvalhoalves 14y ago
What's the use case?
- clarete 14y ago
  I have two main use cases in my mind right now. 1) Making it easier to write tools for testing python code, like sure[0] and freezegun[1] 2) Prototyping new features for python without touching the C code. [0] http://github.com/gabrielfalcao/sure http://github.com/gabrielfalcao/sure -- where forbiddenfruit started) [1] http://github.com/spulec/freezegun http://github.com/spulec/freezegun
- philipbjorge 14y ago
  It's a dirty hack - therefore, fun.
- prezjordan 14y ago
  Probably for the same reason why reopening Ruby classes is used so much. "hello, world".capitalize looks nicer than capitalize("hello, world"), and it's more convenient for method chaining.
pekk 14y ago
If you are doing this for testing, it's already a feature of pytest: http://pytest.org/latest/monkeypatch.html http://pytest.org/latest/monkeypatch.html
- clarete 14y ago
  I might be wrong, but I don't think that it's actually possible to mock built-in objects (written in C, not in python) using pytest. A very quick test would be trying to do something like this: >>> monkeypatch(str, "blah", "bleh") >>> assert str.blah == "bleh" I tried it here with no success though.
jacobolus 14y ago
What are the license implications of using GPLv3 code as part of a test suite?
- clarete 14y ago
  I don't think that there's any implications for that, but I'll probably relicense this library as MIT or at least LGPL pretty soon. I just used my default licence template, which defaults to GPL.
  - marcosmlopes 14y ago
    Wow! Great news. It would be nice have this project under MIT license.
oellegaard 14y ago
While it is a cool project, I hope I never have to work on a project that use this. I hate when people overwrite built-ins, but that might just be me.
tekacs 14y ago
Particularly striking is how little (pure Python) code was required to do this (courtesy ctypes)! A wonderful hack! :) Edit: see https://github.com/clarete/forbiddenfruit/blob/master/forbiddenfruit/__init__.py https://github.com/clarete/forbiddenfruit/blob/master/forbid...
shabble 14y ago
c.f. http://perldoc.perl.org/functions/bless.html http://perldoc.perl.org/functions/bless.html
daGrevis 14y ago
Look good! I would like to see more examples of how to use it in tests tho!

35 points by clarete 14y ago

herge 14y ago

Man, having this as a context manager (maybe with the help of contextlib) would be great, because context managers are great.

clarete 14y ago
That's the idea. Everything to make testing easier! :)

hcarvalhoalves 14y ago

What's the use case?

clarete 14y ago
I have two main use cases in my mind right now. 1) Making it easier to write tools for testing python code, like sure[0] and freezegun[1] 2) Prototyping new features for python without touching the C code. [0] http://github.com/gabrielfalcao/sure http://github.com/gabrielfalcao/sure -- where forbiddenfruit started) [1] http://github.com/spulec/freezegun http://github.com/spulec/freezegun
philipbjorge 14y ago
It's a dirty hack - therefore, fun.
prezjordan 14y ago
Probably for the same reason why reopening Ruby classes is used so much. "hello, world".capitalize looks nicer than capitalize("hello, world"), and it's more convenient for method chaining.

pekk 14y ago

If you are doing this for testing, it's already a feature of pytest: http://pytest.org/latest/monkeypatch.html http://pytest.org/latest/monkeypatch.html

clarete 14y ago
I might be wrong, but I don't think that it's actually possible to mock built-in objects (written in C, not in python) using pytest. A very quick test would be trying to do something like this: >>> monkeypatch(str, "blah", "bleh") >>> assert str.blah == "bleh" I tried it here with no success though.

jacobolus 14y ago

What are the license implications of using GPLv3 code as part of a test suite?

clarete 14y ago
I don't think that there's any implications for that, but I'll probably relicense this library as MIT or at least LGPL pretty soon. I just used my default licence template, which defaults to GPL.
- marcosmlopes 14y ago
  Wow! Great news. It would be nice have this project under MIT license.

oellegaard 14y ago

While it is a cool project, I hope I never have to work on a project that use this. I hate when people overwrite built-ins, but that might just be me.

tekacs 14y ago

Particularly striking is how little (pure Python) code was required to do this (courtesy ctypes)! A wonderful hack! :) Edit: see https://github.com/clarete/forbiddenfruit/blob/master/forbiddenfruit/__init__.py https://github.com/clarete/forbiddenfruit/blob/master/forbid...

shabble 14y ago

c.f. http://perldoc.perl.org/functions/bless.html http://perldoc.perl.org/functions/bless.html

daGrevis 14y ago

Look good! I would like to see more examples of how to use it in tests tho!