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