SlevenBits Cappuccino Development

Installing pyobjc in virtualenv on Mac OS X 10.7

Alexander Ljungberg — Tue, 15 May 2012 00:58:18 +0000

Just ran into a few problems while trying to get pyobjc to install in a new Python virtualenv on Mac OS X 10.7.

First, pip wouldn’t install pyobjc-core nor pyobjc. Turns out pyobjc does some specialised installation stuff not compatible with pip. The error looks like this:

AttributeError: class egg_info has no attribute 'iter_entry_points'

The answer is just to switch to easy_install.

The second error is a compilation error:

Modules/objc/alloc_hack.m: In function ‘call_NSObject_alloc’:
Modules/objc/alloc_hack.m:33: error: Mac OS X version 10.5 or later is
needed for zerocost-exceptions

Not sure what’s going on here but Googling the error indicated it potentially has to do with compiling for a 64 bit platform. Regardless the solution is to change deployment target like so:

export MACOSX_DEPLOYMENT_TARGET=10.5

All in all this is what we get:

mkvirtualenv myenv
export MACOSX_DEPLOYMENT_TARGET=10.5
easy_install pyobjc-core
easy_install pyobjc

Recipe: argparse with Jython 2.5.1

Alexander Ljungberg — Wed, 01 Sep 2010 20:08:08 +0000

To quickly install the new argparse module into Jython 2.5.1, cd into the folder where jython2.5.1 is and run something like this:

wget http://peak.telecommunity.com/dist/ez_setup.py
jython ez_setup.py
jython2.5.1/bin/easy_install argparse

Tested on Mac OS X.

Hexahexacontadecimal

Alexander Ljungberg — Tue, 15 Jun 2010 04:20:48 +0000

Just as Babylonians wisely counted in sexagesimal, the wise web developer is naturally drawn to hexahexacontadecimal. With an alphabet consisting of all unreserved URL characters:

0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_.~

we get a radix of 66, the densest possible way to express a number in a URL. In hexahexacontadecimal the unsightly number 302 231 454 903 657 293 676 544 turns into the sleek i FsG UkO .0t sxw. Behold, the pinnacle of URL numeral systems.

def hexahexacontadecimal_encode_int(n):
  """Represent a number in hexahexacontadecimal."""
  alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_.~"
  if n == 0:
    return alphabet[0]
  r = StringIO()
  while n > 0:
    n, t = divmod(n, 66)
    r.write(alphabet[t])
  return r.getvalue()[::-1]

(You could have called this base66 or base 66 but why would you?)