Today I learned that JSON is much faster than YAML for use in Django fixtures. I sped up the rather slow test suite in an app of mine by nearly a factor of 2 by switching to JSON (the test suite seems to be dominated by time spent parsing fixtures). Here is a handy script I wrote to convert the fixtures:
#!/usr/bin/env python
#
# yaml2json.py
import datetime
import os
import sys
import simplejson
import yaml
class JSONEncoder(simplejson.JSONEncoder):
"""
JSONEncoder subclass that knows how to encode date/time and decimal types.
"""
DATE_FORMAT = "%Y-%m-%d"
TIME_FORMAT = "%H:%M:%S"
def default(self, o):
if isinstance(o, datetime.datetime):
return o.strftime("%s %s" % (self.DATE_FORMAT, self.TIME_FORMAT))
elif isinstance(o, datetime.date):
return o.strftime(self.DATE_FORMAT)
elif isinstance(o, datetime.time):
return o.strftime(self.TIME_FORMAT)
elif isinstance(o, decimal.Decimal):
return str(o)
else:
return super(JSONEncoder, self).default(o)
def main(fname):
assert os.path.splitext(fname)[1] == ".yaml"
with file(fname) as fp:
d = yaml.load(fp)
outname = os.path.splitext(fname)[0] + ".json"
with open(outname, "wb") as fp:
fp.write(JSONEncoder(indent=' ').encode(d))
if __name__ == '__main__':
main(sys.argv[1])
Pass the filename as the first argument, something like this:
for TMP in $(find . -name '*.yaml'); do yaml2json.py $TMP; done
(and you can add git/hg/bzr/svn add and remove commands into that line too).
You will need to update the fixtures attribute in your tests if you specified the ‘.yaml’ extension.