def test_cheat_hash():
'''Test `cheat_hash` on various objects.'''
things = [
1, 7, 4.5, [1, 2, 3.4], (1, 2, 3.4), {
1: 2,
3: 4.5
},
set((1, 2, 3.4)), [1, [1, 2], 3], [1, {
frozenset((1, 2)): 'meow'
}, 3], sum, None, (None, {
None: None
})
]
things_copy = copy.deepcopy(things)
for thing, thing_copy in zip(things, things_copy):
assert cheat_hash(thing) == cheat_hash(thing) == \
cheat_hash(thing_copy) == cheat_hash(thing_copy)
def __init__(self, containing_dict, function, *args, **kwargs):
'''
Construct the `SleekCallArgs`.
`containing_dict` is the `dict` we'll try to remove ourselves from when
one of our sleekrefs dies. `function` is the function for which we
calculate call args from `*args` and `**kwargs`.
'''
self.containing_dict = containing_dict
'''
`dict` we'll try to remove ourselves from when 1 of our sleekrefs dies.
'''
args_spec = cute_inspect.getargspec(function)
star_args_name, star_kwargs_name = \
args_spec.varargs, args_spec.keywords
call_args = cute_inspect.getcallargs(function, *args, **kwargs)
del args, kwargs
self.star_args_refs = []
'''Sleekrefs to star-args.'''
if star_args_name:
star_args = call_args.pop(star_args_name, None)
if star_args:
self.star_args_refs = [SleekRef(star_arg, self.destroy) for
star_arg in star_args]
self.star_kwargs_refs = {}
'''Sleerefs to star-kwargs.'''
if star_kwargs_name:
star_kwargs = call_args.pop(star_kwargs_name, {})
if star_kwargs:
self.star_kwargs_refs = CuteSleekValueDict(self.destroy,
star_kwargs)
self.args_refs = CuteSleekValueDict(self.destroy, call_args)
'''Mapping from argument name to value, sleek-style.'''
# In the future the `.args`, `.star_args` and `.star_kwargs` attributes
# may change, so we must record the hash now:
self._hash = cheat_hashing.cheat_hash(
(
self.args,
self.star_args,
self.star_kwargs
)
)
def test_cheat_hash():
'''Test `cheat_hash` on various objects.'''
things = [
1,
7,
4.5,
[1, 2, 3.4],
(1, 2, 3.4),
{1: 2, 3: 4.5},
set((1, 2, 3.4)),
[1, [1, 2], 3],
[1, {frozenset((1, 2)): 'meow'}, 3],
sum,
None,
(None, {None: None})
]
things_copy = copy.deepcopy(things)
for thing, thing_copy in zip(things, things_copy):
assert cheat_hash(thing) == cheat_hash(thing) == \
cheat_hash(thing_copy) == cheat_hash(thing_copy)
def __init__(self, containing_dict, function, *args, **kwargs):
'''
Construct the `SleekCallArgs`.
`containing_dict` is the `dict` we'll try to remove ourselves from when
one of our sleekrefs dies. `function` is the function for which we
calculate call args from `*args` and `**kwargs`.
'''
self.containing_dict = containing_dict
'''
`dict` we'll try to remove ourselves from when 1 of our sleekrefs dies.
'''
args_spec = cute_inspect.getargspec(function)
star_args_name, star_kwargs_name = \
args_spec.varargs, args_spec.keywords
call_args = cute_inspect.getcallargs(function, *args, **kwargs)
del args, kwargs
self.star_args_refs = []
'''Sleekrefs to star-args.'''
if star_args_name:
star_args = call_args.pop(star_args_name, None)
if star_args:
self.star_args_refs = [
SleekRef(star_arg, self.destroy) for star_arg in star_args
]
self.star_kwargs_refs = {}
'''Sleerefs to star-kwargs.'''
if star_kwargs_name:
star_kwargs = call_args.pop(star_kwargs_name, {})
if star_kwargs:
self.star_kwargs_refs = CuteSleekValueDict(
self.destroy, star_kwargs)
self.args_refs = CuteSleekValueDict(self.destroy, call_args)
'''Mapping from argument name to value, sleek-style.'''
# In the future the `.args`, `.star_args` and `.star_kwargs` attributes
# may change, so we must record the hash now:
self._hash = cheat_hashing.cheat_hash(
(self.args, self.star_args, self.star_kwargs))
def __init__(self, function, *args, **kwargs):
'''
Construct the arguments profile.
`*args` and `**kwargs` are the arguments that go into the `function`.
'''
if not callable(function):
raise Exception('%s is not a callable object.' % function)
self.function = function
raw_args = args
raw_kwargs = kwargs
del args, kwargs
self.args = ()
'''Tuple of positional arguments.'''
self.kwargs = OrderedDict()
'''Ordered dict of keyword arguments.'''
args_spec = cute_inspect.getargspec(function)
(s_args, s_star_args, s_star_kwargs, s_defaults) = args_spec
# `getargspec` has a weird policy, when inspecting a function with no
# defaults, to give a `defaults` of `None` instead of the more
# consistent `()`. We fix that here:
if s_defaults is None:
s_defaults = ()
getcallargs_result = cute_inspect.getcallargs(function,
*raw_args,
**raw_kwargs)
self.getcallargs_result = getcallargs_result
# The number of args which have default values:
n_defaultful_args = len(s_defaults)
# The word "defaultful" means "something which has a default."
#######################################################################
#######################################################################
# Now we'll create the arguments profile, using a 4-phases algorithm. #
# #
#######################################################################
# Phase 1: We specify all the args that don't have a default as
# positional args:
defaultless_args = s_args[:-n_defaultful_args] if n_defaultful_args \
else s_args[:]
self.args += tuple(
dict_tools.get_list(getcallargs_result, defaultless_args)
)
#######################################################################
# Phase 2: We now have to deal with args that have a default. Some of
# them, possibly none and possibly all of them, should be given
# positionally. Some of them, possibly none, should be given by
# keyword. And some of them, possibly none and possibly all of them,
# should not be given at all. It is our job to figure out in which way
# each argument should be given.
# In this variable:
n_defaultful_args_to_specify_positionally = None
# We will put the number of defaultful arguments that should be
# specified positionally.
defaultful_args = s_args[-n_defaultful_args:] if n_defaultful_args \
else []
# `dict` that maps from argument name to default value:
defaults = OrderedDict(zip(defaultful_args, s_defaults))
defaultful_args_differing_from_defaults = set((
defaultful_arg for defaultful_arg in defaultful_args
if defaults[defaultful_arg] != getcallargs_result[defaultful_arg]
))
if s_star_args and getcallargs_result[s_star_args]:
# We have some arguments that go into `*args`! This means that we
# don't even need to think hard, we can already be sure that we're
# going to have to specify *all* of the defaultful arguments
# positionally, otherwise it will be impossible to put arguments in
# `*args`.
n_defaultful_args_to_specify_positionally = n_defaultful_args
else:
# `dict` mapping from each defaultful arg to the "price" of
# specifying its value:
prices_of_values = OrderedDict((
(defaultful_arg, len(repr(getcallargs_result[defaultful_arg])))
for defaultful_arg in defaultful_args
))
# The price is simply the string length of the value's `repr`.
# `dict` mapping from each defaultful arg to the "price" of
# specifying it as a keyword (not including the length of the
# value):
prices_of_keyword_prefixes = OrderedDict(
((defaultful_arg, len(defaultful_arg)+1) for
defaultful_arg in defaultful_args)
)
# For example, if we have a defaultful arg "gravity_strength", then
# specifiying it by keyword will require using the string
# "gravity_strength=", which is 17 characters long, therefore the
# price is 17.
# Now we need to decide just how many defaultful args we are going
# to specify positionally. The options are anything from `0` to
# `n_defaultful_args`. We're going to go one by one, and calcluate
# the price for each candidate, and put it in this dict:
total_price_for_n_dasp_candidate = OrderedDict()
# (The `n_dasp` here is an abbreivation of the
# `n_defaultful_args_to_specify_positionally` variable defined
# before.)
#
# After we have the price for each option, we'll select the one
# with the lowest price.
# One thing to do before iterating on the candidates is to find out
# whether the "lonely comma discount" is in effect.
#
# The "lonely comma discount" is given when there's nothing but
# defaultful arguments to this function, and therefore the number
# of ", " strings needed here is not `candidate`, but `candidate -
# 1`, unless of course candidate is zero.
if not defaultless_args and \
(not s_star_args or not getcallargs_result[s_star_args]) and \
(not s_star_kwargs or not getcallargs_result[s_star_kwargs]):
lonely_comma_discount_may_be_given = True
else:
lonely_comma_discount_may_be_given = False
# Now we iterate on the candidates to find out which one has the
# lowest price:
for candidate in xrange(n_defaultful_args + 1):
defaultful_args_to_specify_positionally = \
defaultful_args[:candidate]
price_for_positionally_specified_defaultful_args = \
2 * candidate + \
sum(
dict_tools.get_list(
prices_of_values,
defaultful_args_to_specify_positionally
)
)
# The `2 * candidate` addend is to account for the ", " parts
# between the arguments.
defaultful_args_to_specify_by_keyword = filter(
defaultful_args_differing_from_defaults.__contains__,
defaultful_args[candidate:]
)
price_for_defaultful_args_specified_by_keyword = \
2 * len(defaultful_args_to_specify_by_keyword) + \
sum(
dict_tools.get_list(
prices_of_keyword_prefixes,
defaultful_args_to_specify_by_keyword
)
) + \
sum(
dict_tools.get_list(
prices_of_values,
defaultful_args_to_specify_by_keyword
)
)
# The `2 * len(...)` addend is to account for the ", " parts
# between the arguments.
# Now we need to figure out if this candidate gets the "lonely
# comma discount".
if lonely_comma_discount_may_be_given and \
(defaultful_args_to_specify_by_keyword or \
defaultful_args_to_specify_positionally):
lonely_comma_discount = -2
else:
lonely_comma_discount = 0
price = price_for_positionally_specified_defaultful_args + \
price_for_defaultful_args_specified_by_keyword + \
lonely_comma_discount
total_price_for_n_dasp_candidate[candidate] = price
# Finished iterating on candidates! Time to pick our winner.
minimum_price = min(total_price_for_n_dasp_candidate.itervalues())
leading_candidates = [
candidate for candidate in
total_price_for_n_dasp_candidate.iterkeys() if
total_price_for_n_dasp_candidate[candidate] == minimum_price
]
if len(leading_candidates) == 1:
# We finished with one candidate which has the minimum price.
# This is our winner.
(winner,) = leading_candidates
n_defaultful_args_to_specify_positionally = winner
else:
# We have a draw! We're gonna have to settle it by picking the
# lowest candidate, because in our definition of "canonical
# arguments profile", our second priority after "as few
# characters as possible" is "as many keyword arguments as
# possible".
winner = leading_candidates[0]
n_defaultful_args_to_specify_positionally = winner
# We have a winner! Now we know exactly which defaultful args should
# be specified positionally and which should be specified by
# keyword.
# First we add the positionally specified:
defaultful_args_to_specify_positionally = \
defaultful_args[:n_defaultful_args_to_specify_positionally]
self.args += tuple(
(getcallargs_result[defaultful_arg] for defaultful_arg
in defaultful_args_to_specify_positionally)
)
# Now we add those specified by keyword:
defaultful_args_to_specify_by_keyword = filter(
defaultful_args_differing_from_defaults.__contains__,
defaultful_args[n_defaultful_args_to_specify_positionally:]
)
for defaultful_arg in defaultful_args_to_specify_by_keyword:
self.kwargs[defaultful_arg] = getcallargs_result[defaultful_arg]
#######################################################################
# Phase 3: Add the star args:
if s_star_args and getcallargs_result[s_star_args]:
assert not self.kwargs
# Just making sure that no non-star args were specified by keyword,
# which would make it impossible for us to put stuff in `*args`.
self.args += getcallargs_result[s_star_args]
#######################################################################
# Phase 4: Add the star kwargs:
if s_star_kwargs and getcallargs_result[s_star_kwargs]:
# We can't just add the `**kwargs` as is; we need to add them
# according to canonical ordering. So we need to sort them first.
unsorted_star_kwargs_names = \
getcallargs_result[s_star_kwargs].keys()
sorted_star_kwargs_names = sorted(
unsorted_star_kwargs_names,
cmp=cmp_tools.underscore_hating_cmp
)
sorted_star_kwargs = OrderedDict(
zip(
sorted_star_kwargs_names,
dict_tools.get_list(
getcallargs_result[s_star_kwargs],
sorted_star_kwargs_names
)
)
)
self.kwargs.update(sorted_star_kwargs)
# Our 4-phases algorithm is done! The argument profile is canonical. #
#######################################################################
#######################################################################
#######################################################################
# Now a bit of post-processing:
_arguments = OrderedDict()
dict_of_positional_arguments = OrderedDict(
dict_tools.filter_items(
getcallargs_result,
lambda key, value: ((key not in self.kwargs) and \
(key != s_star_args) and \
(key != s_star_kwargs))
)
)
dict_of_positional_arguments.sort(key=s_args.index)
_arguments.update(dict_of_positional_arguments)
if s_star_args:
_arguments['*'] = getcallargs_result[s_star_args]
_arguments.update(self.kwargs)
self._arguments = _arguments
'''Ordered dict of arguments, both positional- and keyword-.'''
# Caching the hash, since its computation can take a long time:
self._hash = cheat_hashing.cheat_hash(
(
self.function,
self.args,
tuple(self.kwargs)
)
)
def __init__(self, function, *args, **kwargs):
'''
Construct the arguments profile.
`*args` and `**kwargs` are the arguments that go into the `function`.
'''
if not callable(function):
raise Exception('%s is not a callable object.' % function)
self.function = function
raw_args = args
raw_kwargs = kwargs
del args, kwargs
self.args = ()
'''Tuple of positional arguments.'''
self.kwargs = OrderedDict()
'''Ordered dict of keyword arguments.'''
args_spec = cute_inspect.getargspec(function)
(s_args, s_star_args, s_star_kwargs, s_defaults) = args_spec
# `getargspec` has a weird policy, when inspecting a function with no
# defaults, to give a `defaults` of `None` instead of the more
# consistent `()`. We fix that here:
if s_defaults is None:
s_defaults = ()
getcallargs_result = cute_inspect.getcallargs(function, *raw_args,
**raw_kwargs)
self.getcallargs_result = getcallargs_result
# The number of args which have default values:
n_defaultful_args = len(s_defaults)
# The word "defaultful" means "something which has a default."
#######################################################################
#######################################################################
# Now we'll create the arguments profile, using a 4-phases algorithm. #
# #
#######################################################################
# Phase 1: We specify all the args that don't have a default as
# positional args:
defaultless_args = s_args[:-n_defaultful_args] if n_defaultful_args \
else s_args[:]
self.args += tuple(
dict_tools.get_list(getcallargs_result, defaultless_args))
#######################################################################
# Phase 2: We now have to deal with args that have a default. Some of
# them, possibly none and possibly all of them, should be given
# positionally. Some of them, possibly none, should be given by
# keyword. And some of them, possibly none and possibly all of them,
# should not be given at all. It is our job to figure out in which way
# each argument should be given.
# In this variable:
n_defaultful_args_to_specify_positionally = None
# We will put the number of defaultful arguments that should be
# specified positionally.
defaultful_args = s_args[-n_defaultful_args:] if n_defaultful_args \
else []
# `dict` that maps from argument name to default value:
defaults = OrderedDict(zip(defaultful_args, s_defaults))
defaultful_args_differing_from_defaults = set((
defaultful_arg for defaultful_arg in defaultful_args
if defaults[defaultful_arg] != getcallargs_result[defaultful_arg]))
if s_star_args and getcallargs_result[s_star_args]:
# We have some arguments that go into `*args`! This means that we
# don't even need to think hard, we can already be sure that we're
# going to have to specify *all* of the defaultful arguments
# positionally, otherwise it will be impossible to put arguments in
# `*args`.
n_defaultful_args_to_specify_positionally = n_defaultful_args
else:
# `dict` mapping from each defaultful arg to the "price" of
# specifying its value:
prices_of_values = OrderedDict(
((defaultful_arg,
len(repr(getcallargs_result[defaultful_arg])))
for defaultful_arg in defaultful_args))
# The price is simply the string length of the value's `repr`.
# `dict` mapping from each defaultful arg to the "price" of
# specifying it as a keyword (not including the length of the
# value):
prices_of_keyword_prefixes = OrderedDict(
((defaultful_arg, len(defaultful_arg) + 1)
for defaultful_arg in defaultful_args))
# For example, if we have a defaultful arg "gravity_strength", then
# specifiying it by keyword will require using the string
# "gravity_strength=", which is 17 characters long, therefore the
# price is 17.
# Now we need to decide just how many defaultful args we are going
# to specify positionally. The options are anything from `0` to
# `n_defaultful_args`. We're going to go one by one, and calcluate
# the price for each candidate, and put it in this dict:
total_price_for_n_dasp_candidate = OrderedDict()
# (The `n_dasp` here is an abbreivation of the
# `n_defaultful_args_to_specify_positionally` variable defined
# before.)
#
# After we have the price for each option, we'll select the one
# with the lowest price.
# One thing to do before iterating on the candidates is to find out
# whether the "lonely comma discount" is in effect.
#
# The "lonely comma discount" is given when there's nothing but
# defaultful arguments to this function, and therefore the number
# of ", " strings needed here is not `candidate`, but `candidate -
# 1`, unless of course candidate is zero.
if not defaultless_args and \
(not s_star_args or not getcallargs_result[s_star_args]) and \
(not s_star_kwargs or not getcallargs_result[s_star_kwargs]):
lonely_comma_discount_may_be_given = True
else:
lonely_comma_discount_may_be_given = False
# Now we iterate on the candidates to find out which one has the
# lowest price:
for candidate in xrange(n_defaultful_args + 1):
defaultful_args_to_specify_positionally = \
defaultful_args[:candidate]
price_for_positionally_specified_defaultful_args = \
2 * candidate + \
sum(
dict_tools.get_list(
prices_of_values,
defaultful_args_to_specify_positionally
)
)
# The `2 * candidate` addend is to account for the ", " parts
# between the arguments.
defaultful_args_to_specify_by_keyword = filter(
defaultful_args_differing_from_defaults.__contains__,
defaultful_args[candidate:])
price_for_defaultful_args_specified_by_keyword = \
2 * len(defaultful_args_to_specify_by_keyword) + \
sum(
dict_tools.get_list(
prices_of_keyword_prefixes,
defaultful_args_to_specify_by_keyword
)
) + \
sum(
dict_tools.get_list(
prices_of_values,
defaultful_args_to_specify_by_keyword
)
)
# The `2 * len(...)` addend is to account for the ", " parts
# between the arguments.
# Now we need to figure out if this candidate gets the "lonely
# comma discount".
if lonely_comma_discount_may_be_given and \
(defaultful_args_to_specify_by_keyword or \
defaultful_args_to_specify_positionally):
lonely_comma_discount = -2
else:
lonely_comma_discount = 0
price = price_for_positionally_specified_defaultful_args + \
price_for_defaultful_args_specified_by_keyword + \
lonely_comma_discount
total_price_for_n_dasp_candidate[candidate] = price
# Finished iterating on candidates! Time to pick our winner.
minimum_price = min(total_price_for_n_dasp_candidate.itervalues())
leading_candidates = [
candidate
for candidate in total_price_for_n_dasp_candidate.iterkeys()
if total_price_for_n_dasp_candidate[candidate] == minimum_price
]
if len(leading_candidates) == 1:
# We finished with one candidate which has the minimum price.
# This is our winner.
(winner, ) = leading_candidates
n_defaultful_args_to_specify_positionally = winner
else:
# We have a draw! We're gonna have to settle it by picking the
# lowest candidate, because in our definition of "canonical
# arguments profile", our second priority after "as few
# characters as possible" is "as many keyword arguments as
# possible".
winner = leading_candidates[0]
n_defaultful_args_to_specify_positionally = winner
# We have a winner! Now we know exactly which defaultful args should
# be specified positionally and which should be specified by
# keyword.
# First we add the positionally specified:
defaultful_args_to_specify_positionally = \
defaultful_args[:n_defaultful_args_to_specify_positionally]
self.args += tuple(
(getcallargs_result[defaultful_arg]
for defaultful_arg in defaultful_args_to_specify_positionally))
# Now we add those specified by keyword:
defaultful_args_to_specify_by_keyword = filter(
defaultful_args_differing_from_defaults.__contains__,
defaultful_args[n_defaultful_args_to_specify_positionally:])
for defaultful_arg in defaultful_args_to_specify_by_keyword:
self.kwargs[defaultful_arg] = getcallargs_result[defaultful_arg]
#######################################################################
# Phase 3: Add the star args:
if s_star_args and getcallargs_result[s_star_args]:
assert not self.kwargs
# Just making sure that no non-star args were specified by keyword,
# which would make it impossible for us to put stuff in `*args`.
self.args += getcallargs_result[s_star_args]
#######################################################################
# Phase 4: Add the star kwargs:
if s_star_kwargs and getcallargs_result[s_star_kwargs]:
# We can't just add the `**kwargs` as is; we need to add them
# according to canonical ordering. So we need to sort them first.
unsorted_star_kwargs_names = \
getcallargs_result[s_star_kwargs].keys()
sorted_star_kwargs_names = sorted(
unsorted_star_kwargs_names,
cmp=cmp_tools.underscore_hating_cmp)
sorted_star_kwargs = OrderedDict(
zip(
sorted_star_kwargs_names,
dict_tools.get_list(getcallargs_result[s_star_kwargs],
sorted_star_kwargs_names)))
self.kwargs.update(sorted_star_kwargs)
# Our 4-phases algorithm is done! The argument profile is canonical. #
#######################################################################
#######################################################################
#######################################################################
# Now a bit of post-processing:
_arguments = OrderedDict()
dict_of_positional_arguments = OrderedDict(
dict_tools.filter_items(
getcallargs_result,
lambda key, value: ((key not in self.kwargs) and \
(key != s_star_args) and \
(key != s_star_kwargs))
)
)
dict_of_positional_arguments.sort(key=s_args.index)
_arguments.update(dict_of_positional_arguments)
if s_star_args:
_arguments['*'] = getcallargs_result[s_star_args]
_arguments.update(self.kwargs)
self._arguments = _arguments
'''Ordered dict of arguments, both positional- and keyword-.'''
# Caching the hash, since its computation can take a long time:
self._hash = cheat_hashing.cheat_hash(
(self.function, self.args, tuple(self.kwargs)))
