Pytz error: unpack requires a string argument of length 44

[bringa at gmail.com]

Hi!

I'm trying to get a handle on pytz (http://pytz.sourceforge.net/). I don't have root on the system I'll be running my script on, so I need to go for a local installation. I copied pytz into a folder in my sys.path and am importing from there. That part seems to work. I downloaded the tarball on http://pypi.python.org/pypi/pytz/#downloads

So now I'm walking through the examples on http://pytz.sourceforge.net/#example-usage. This is what happens:

Python 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from datetime import datetime, timedelta
>>> from pytz import timezone
>>> import pytz
>>> utc = pytz.utc
>>> utc.zone
'UTC'
>>> eastern = timezone('US/Eastern')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "C:\code\SoF\serversonfire\pytz\__init__.py", line 181, in timezone
    _tzinfo_cache[zone] = build_tzinfo(zone, fp)
  File "C:\code\SoF\serversonfire\pytz\tzfile.py", line 30, in build_tzinfo
    typecnt, charcnt) =  unpack(head_fmt, fp.read(head_size))
error: unpack requires a string argument of length 44


Can anyone explain to me why that call fails?