symposion_app/registrasion/util.py
2016-09-20 13:47:59 +10:00

74 lines
1.9 KiB
Python

import string
import sys
from django.utils.crypto import get_random_string
def generate_access_code():
''' Generates an access code for users' payments as well as their
fulfilment code for check-in.
The access code will 4 characters long, which allows for 1,500,625
unique codes, which really should be enough for anyone. '''
length = 4
# all upper-case letters + digits 1-9 (no 0 vs O confusion)
chars = string.uppercase + string.digits[1:]
# 4 chars => 35 ** 4 = 1500625 (should be enough for anyone)
return get_random_string(length=length, allowed_chars=chars)
def all_arguments_optional(ntcls):
''' Takes a namedtuple derivative and makes all of the arguments optional.
'''
ntcls.__new__.__defaults__ = (
(None,) * len(ntcls._fields)
)
return ntcls
def lazy(function, *args, **kwargs):
''' Produces a callable so that functions can be lazily evaluated in
templates.
Arguments:
function (callable): The function to call at evaluation time.
args: Positional arguments, passed directly to ``function``.
kwargs: Keyword arguments, passed directly to ``function``.
Return:
callable: A callable that will evaluate a call to ``function`` with
the specified arguments.
'''
NOT_EVALUATED = object()
retval = [NOT_EVALUATED]
def evaluate():
if retval[0] is NOT_EVALUATED:
retval[0] = function(*args, **kwargs)
return retval[0]
return evaluate
def get_object_from_name(name):
''' Returns the named object.
Arguments:
name (str): A string of form `package.subpackage.etc.module.property`.
This function will import `package.subpackage.etc.module` and
return `property` from that module.
'''
dot = name.rindex(".")
mod_name, property_name = name[:dot], name[dot + 1:]
__import__(mod_name)
return getattr(sys.modules[mod_name], property_name)