boolify() - Code Metrics - kalefranz/auxlib - Measure and Improve Code Quality continuously with Scrutinizer

boolify() F
last analyzed 2017-05-18 17:16 UTC

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Complexity

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Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes	3
Bugs	0	Features	0

Metric	Value
cc	10
c	3
b	0
f	0
dl	0
loc	44
rs	3.1304

How to fix Complexity

"""Collection of functions to coerce conversion of types with an intelligent guess."""
from collections import Mapping
from itertools import chain
from re import IGNORECASE, compile

from enum import Enum

from .compat import NoneType, integer_types, isiterable, iteritems, string_types, text_type
from .decorators import memoizeproperty
from .exceptions import AuxlibError

__all__ = ["boolify", "typify", "maybecall", "listify", "numberify"]

BOOLISH_TRUE = ("true", "yes", "on", "y")
BOOLISH_FALSE = ("false", "off", "n", "no", "non", "none", "")
NULL_STRINGS = ("none", "~", "null", "\0")
BOOL_COERCEABLE_TYPES = integer_types + (bool, float, complex, list, set, dict, tuple)
NUMBER_TYPES = integer_types + (float, complex)
NUMBER_TYPES_SET = set(NUMBER_TYPES)
STRING_TYPES_SET = set(string_types)

NO_MATCH = object()


class TypeCoercionError(AuxlibError, ValueError):

    def __init__(self, value, msg, *args, **kwargs):
        self.value = value
        super(TypeCoercionError, self).__init__(msg, *args, **kwargs)


class _Regex(object):

    @memoizeproperty
    def BOOLEAN_TRUE(self):
        return compile(r'^true$|^yes$|^on$', IGNORECASE), True

    @memoizeproperty
    def BOOLEAN_FALSE(self):
        return compile(r'^false$|^no$|^off$', IGNORECASE), False

    @memoizeproperty
    def NONE(self):
        return compile(r'^none$|^null$', IGNORECASE), None

    @memoizeproperty
    def INT(self):
        return compile(r'^[-+]?\d+$'), int

    @memoizeproperty
    def BIN(self):
        return compile(r'^[-+]?0[bB][01]+$'), bin

    @memoizeproperty
    def OCT(self):
        return compile(r'^[-+]?0[oO][0-7]+$'), oct

    @memoizeproperty
    def HEX(self):
        return compile(r'^[-+]?0[xX][0-9a-fA-F]+$'), hex

    @memoizeproperty
    def FLOAT(self):
        return compile(r'^[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?$'), float

    @memoizeproperty
    def COMPLEX(self):
        return (compile(r'^(?:[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)?'  # maybe first float
                        r'[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?j$'),     # second float with j
                complex)

    @property
    def numbers(self):
        yield self.INT
        yield self.FLOAT
        yield self.BIN
        yield self.OCT
        yield self.HEX
        yield self.COMPLEX

    @property
    def boolean(self):
        yield self.BOOLEAN_TRUE
        yield self.BOOLEAN_FALSE

    @property
    def none(self):
        yield self.NONE

    def convert_number(self, value_string):
        return self._convert(value_string, (self.numbers, ))

    def convert(self, value_string):
        return self._convert(value_string, (self.boolean, self.none, self.numbers, ))

    def _convert(self, value_string, type_list):
        return next((typish(value_string) if callable(typish) else typish
                     for regex, typish in chain.from_iterable(type_list)
                     if regex.match(value_string)),
                    NO_MATCH)

_REGEX = _Regex()


def numberify(value):
    """

    Examples:
        >>> [numberify(x) for x in ('1234', 1234, '0755', 0o0755, False, 0, '0', True, 1, '1')]
          [1234, 1234, 755, 493, 0, 0, 0, 1, 1, 1]
        >>> [numberify(x) for x in ('12.34', 12.34, 1.2+3.5j, '1.2+3.5j')]
        [12.34, 12.34, (1.2+3.5j), (1.2+3.5j)]

    """
    if isinstance(value, bool):
        return int(value)
    if isinstance(value, NUMBER_TYPES):
        return value
    candidate = _REGEX.convert_number(value)
    if candidate is not NO_MATCH:
        return candidate
    raise TypeCoercionError(value, "Cannot convert {0} to a number.".format(value))


def boolify(value, nullable=False, return_string=False):
    """Convert a number, string, or sequence type into a pure boolean.

    Args:
        value (number, string, sequence): pretty much anything

    Returns:
        bool: boolean representation of the given value

    Examples:
        >>> [boolify(x) for x in ('yes', 'no')]
        [True, False]
        >>> [boolify(x) for x in (0.1, 0+0j, True, '0', '0.0', '0.1', '2')]
        [True, False, True, False, False, True, True]
        >>> [boolify(x) for x in ("true", "yes", "on", "y")]
        [True, True, True, True]
        >>> [boolify(x) for x in ("no", "non", "none", "off", "")]
        [False, False, False, False, False]
        >>> [boolify(x) for x in ([], set(), dict(), tuple())]
        [False, False, False, False]
        >>> [boolify(x) for x in ([1], set([False]), dict({'a': 1}), tuple([2]))]
        [True, True, True, True]

    """
    # cast number types naturally
    if isinstance(value, BOOL_COERCEABLE_TYPES):
        return bool(value)
    # try to coerce string into number
    val = text_type(value).strip().lower().replace('.', '', 1)
    if val.isnumeric():
        return bool(float(val))
    elif val in BOOLISH_TRUE:
        return True
    elif nullable and val in NULL_STRINGS:
        return None
    elif val in BOOLISH_FALSE:
        return False
    else:  # must be False
        try:
            return bool(complex(val))
        except ValueError:
            if isinstance(value, string_types) and return_string:
                return value
            raise TypeCoercionError(value, "The value %r cannot be boolified." % value)


def boolify_truthy_string_ok(value):
    try:
        return boolify(value)
    except ValueError:
        assert isinstance(value, string_types), repr(value)
        return True


def typify_str_no_hint(value):
    candidate = _REGEX.convert(value)
    return candidate if candidate is not NO_MATCH else value


def typify(value, type_hint=None):
    """Take a primitive value, usually a string, and try to make a more relevant type out of it.
    An optional type_hint will try to coerce the value to that type.

    Args:
        value (Any): Usually a string, not a sequence
        type_hint (type or Tuple[type]):

    Examples:
        >>> typify('32')
        32
        >>> typify('32', float)
        32.0
        >>> typify('32.0')
        32.0
        >>> typify('32.0.0')
        '32.0.0'
        >>> [typify(x) for x in ('true', 'yes', 'on')]
        [True, True, True]
        >>> [typify(x) for x in ('no', 'FALSe', 'off')]
        [False, False, False]
        >>> [typify(x) for x in ('none', 'None', None)]
        [None, None, None]

    """
    # value must be a string, or there at least needs to be a type hint
    if isinstance(value, string_types):
        value = value.strip()
    elif type_hint is None:
        # can't do anything because value isn't a string and there's no type hint
        return value

    # now we either have a stripped string, a type hint, or both
    # use the hint if it exists
    if isiterable(type_hint):
        if isinstance(type_hint, type) and issubclass(type_hint, Enum):
            try:
                return type_hint(value)
            except ValueError:
                return type_hint[value]
        type_hint = set(type_hint)
        if not (type_hint - NUMBER_TYPES_SET):
            return numberify(value)
        elif not (type_hint - STRING_TYPES_SET):
            return text_type(value)
        elif not (type_hint - {bool, NoneType}):
            return boolify(value, nullable=True)
        elif not (type_hint - (STRING_TYPES_SET | {bool})):
            return boolify(value, return_string=True)
        elif not (type_hint - (STRING_TYPES_SET | {NoneType})):
            value = text_type(value)
            return None if value.lower() == 'none' else value
        elif not (type_hint - {bool, int}):
            return typify_str_no_hint(text_type(value))
        else:
            raise NotImplementedError()
    elif type_hint is not None:
        # coerce using the type hint, or use boolify for bool
        try:
            return boolify(value) if type_hint == bool else type_hint(value)
        except ValueError as e:
            # ValueError: invalid literal for int() with base 10: 'nope'
            raise TypeCoercionError(value, text_type(e))
    else:
        # no type hint, but we know value is a string, so try to match with the regex patterns
        #   if there's still no match, `typify_str_no_hint` will return `value`
        return typify_str_no_hint(value)


def typify_data_structure(value, type_hint=None):
    if isinstance(value, Mapping):
        return type(value)((k, typify(v, type_hint)) for k, v in iteritems(value))
    elif isiterable(value):
        return type(value)(typify(v, type_hint) for v in value)
    else:
        return typify(value, type_hint)


def maybecall(value):
    return value() if callable(value) else value


def listify(val, return_type=tuple):
    """
    Examples:
        >>> listify('abc', return_type=list)
        ['abc']
        >>> listify(None)
        ()
        >>> listify(False)
        (False,)
        >>> listify(('a', 'b', 'c'), return_type=list)
        ['a', 'b', 'c']
    """
    # TODO: flatlistify((1, 2, 3), 4, (5, 6, 7))
    if val is None:
        return return_type()
    elif isiterable(val):
        return return_type(val)
    else:
        return return_type((val, ))


1			"""Collection of functions to coerce conversion of types with an intelligent guess."""
2			from collections import Mapping
3			from itertools import chain
4			from re import IGNORECASE, compile
5
6			from enum import Enum
7
8			from .compat import NoneType, integer_types, isiterable, iteritems, string_types, text_type
9			from .decorators import memoizeproperty
10			from .exceptions import AuxlibError
11
12			__all__ = ["boolify", "typify", "maybecall", "listify", "numberify"]
13
14			BOOLISH_TRUE = ("true", "yes", "on", "y")
15			BOOLISH_FALSE = ("false", "off", "n", "no", "non", "none", "")
16			NULL_STRINGS = ("none", "~", "null", "\0")
17			BOOL_COERCEABLE_TYPES = integer_types + (bool, float, complex, list, set, dict, tuple)
18			NUMBER_TYPES = integer_types + (float, complex)
19			NUMBER_TYPES_SET = set(NUMBER_TYPES)
20			STRING_TYPES_SET = set(string_types)
21
22			NO_MATCH = object()
23
24
25			class TypeCoercionError(AuxlibError, ValueError):
26
27			def __init__(self, value, msg, args, *kwargs):
28			self.value = value
29			super(TypeCoercionError, self).__init__(msg, args, *kwargs)
30
31
32			class _Regex(object):
33
34			@memoizeproperty
35			def BOOLEAN_TRUE(self):
36			return compile(r'^true$\|^yes$\|^on$', IGNORECASE), True
37
38			@memoizeproperty
39			def BOOLEAN_FALSE(self):
40			return compile(r'^false$\|^no$\|^off$', IGNORECASE), False
41
42			@memoizeproperty
43			def NONE(self):
44			return compile(r'^none$\|^null$', IGNORECASE), None
45
46			@memoizeproperty
47			def INT(self):
48			return compile(r'^[-+]?\d+$'), int
49
50			@memoizeproperty
51			def BIN(self):
52			return compile(r'^[-+]?0[bB][01]+$'), bin
53
54			@memoizeproperty
55			def OCT(self):
56			return compile(r'^[-+]?0[oO][0-7]+$'), oct
57
58			@memoizeproperty
59			def HEX(self):
60			return compile(r'^[-+]?0[xX][0-9a-fA-F]+$'), hex
61
62			@memoizeproperty
63			def FLOAT(self):
64			return compile(r'^[-+]?(\d+(\.\d*)?\|\.\d+)([eE][-+]?\d+)?$'), float
65
66			@memoizeproperty
67			def COMPLEX(self):
68			return (compile(r'^(?:[-+]?(\d+(\.\d*)?\|\.\d+)([eE][-+]?\d+)?)?' # maybe first float
69			r'[-+]?(\d+(\.\d*)?\|\.\d+)([eE][-+]?\d+)?j$'), # second float with j
70			complex)
71
72			@property
73			def numbers(self):
74			yield self.INT
75			yield self.FLOAT
76			yield self.BIN
77			yield self.OCT
78			yield self.HEX
79			yield self.COMPLEX
80
81			@property
82			def boolean(self):
83			yield self.BOOLEAN_TRUE
84			yield self.BOOLEAN_FALSE
85
86			@property
87			def none(self):
88			yield self.NONE
89
90			def convert_number(self, value_string):
91			return self._convert(value_string, (self.numbers, ))
92
93			def convert(self, value_string):
94			return self._convert(value_string, (self.boolean, self.none, self.numbers, ))
95
96			def _convert(self, value_string, type_list):
97			return next((typish(value_string) if callable(typish) else typish
98			for regex, typish in chain.from_iterable(type_list)
99			if regex.match(value_string)),
100			NO_MATCH)
101
102			_REGEX = _Regex()
103
104
105			def numberify(value):
106			"""
107
108			Examples:
109			>>> [numberify(x) for x in ('1234', 1234, '0755', 0o0755, False, 0, '0', True, 1, '1')]
110			[1234, 1234, 755, 493, 0, 0, 0, 1, 1, 1]
111			>>> [numberify(x) for x in ('12.34', 12.34, 1.2+3.5j, '1.2+3.5j')]
112			[12.34, 12.34, (1.2+3.5j), (1.2+3.5j)]
113
114			"""
115			if isinstance(value, bool):
116			return int(value)
117			if isinstance(value, NUMBER_TYPES):
118			return value
119			candidate = _REGEX.convert_number(value)
120			if candidate is not NO_MATCH:
121			return candidate
122			raise TypeCoercionError(value, "Cannot convert {0} to a number.".format(value))
123
124
125			def boolify(value, nullable=False, return_string=False):
126			"""Convert a number, string, or sequence type into a pure boolean.
127
128			Args:
129			value (number, string, sequence): pretty much anything
130
131			Returns:
132			bool: boolean representation of the given value
133
134			Examples:
135			>>> [boolify(x) for x in ('yes', 'no')]
136			[True, False]
137			>>> [boolify(x) for x in (0.1, 0+0j, True, '0', '0.0', '0.1', '2')]
138			[True, False, True, False, False, True, True]
139			>>> [boolify(x) for x in ("true", "yes", "on", "y")]
140			[True, True, True, True]
141			>>> [boolify(x) for x in ("no", "non", "none", "off", "")]
142			[False, False, False, False, False]
143			>>> [boolify(x) for x in ([], set(), dict(), tuple())]
144			[False, False, False, False]
145			>>> [boolify(x) for x in ([1], set([False]), dict({'a': 1}), tuple([2]))]
146			[True, True, True, True]
147
148			"""
149			# cast number types naturally
150			if isinstance(value, BOOL_COERCEABLE_TYPES):
151			return bool(value)
152			# try to coerce string into number
153			val = text_type(value).strip().lower().replace('.', '', 1)
154			if val.isnumeric():
155			return bool(float(val))
156			elif val in BOOLISH_TRUE:
157			return True
158			elif nullable and val in NULL_STRINGS:
159			return None
160			elif val in BOOLISH_FALSE:
161			return False
162			else: # must be False
163			try:
164			return bool(complex(val))
165			except ValueError:
166			if isinstance(value, string_types) and return_string:
167			return value
168			raise TypeCoercionError(value, "The value %r cannot be boolified." % value)
169
170
171			def boolify_truthy_string_ok(value):
172			try:
173			return boolify(value)
174			except ValueError:
175			assert isinstance(value, string_types), repr(value)
176			return True
177
178
179			def typify_str_no_hint(value):
180			candidate = _REGEX.convert(value)
181			return candidate if candidate is not NO_MATCH else value
182
183
184			def typify(value, type_hint=None):
185			"""Take a primitive value, usually a string, and try to make a more relevant type out of it.
186			An optional type_hint will try to coerce the value to that type.
187
188			Args:
189			value (Any): Usually a string, not a sequence
190			type_hint (type or Tuple[type]):
191
192			Examples:
193			>>> typify('32')
194			32
195			>>> typify('32', float)
196			32.0
197			>>> typify('32.0')
198			32.0
199			>>> typify('32.0.0')
200			'32.0.0'
201			>>> [typify(x) for x in ('true', 'yes', 'on')]
202			[True, True, True]
203			>>> [typify(x) for x in ('no', 'FALSe', 'off')]
204			[False, False, False]
205			>>> [typify(x) for x in ('none', 'None', None)]
206			[None, None, None]
207
208			"""
209			# value must be a string, or there at least needs to be a type hint
210			if isinstance(value, string_types):
211			value = value.strip()
212			elif type_hint is None:
213			# can't do anything because value isn't a string and there's no type hint
214			return value
215
216			# now we either have a stripped string, a type hint, or both
217			# use the hint if it exists
218			if isiterable(type_hint):
219			if isinstance(type_hint, type) and issubclass(type_hint, Enum):
220			try:
221			return type_hint(value)
222			except ValueError:
223			return type_hint[value]
224			type_hint = set(type_hint)
225			if not (type_hint - NUMBER_TYPES_SET):
226			return numberify(value)
227			elif not (type_hint - STRING_TYPES_SET):
228			return text_type(value)
229			elif not (type_hint - {bool, NoneType}):
230			return boolify(value, nullable=True)
231			elif not (type_hint - (STRING_TYPES_SET \| {bool})):
232			return boolify(value, return_string=True)
233			elif not (type_hint - (STRING_TYPES_SET \| {NoneType})):
234			value = text_type(value)
235			return None if value.lower() == 'none' else value
236			elif not (type_hint - {bool, int}):
237			return typify_str_no_hint(text_type(value))
238			else:
239			raise NotImplementedError()
240			elif type_hint is not None:
241			# coerce using the type hint, or use boolify for bool
242			try:
243			return boolify(value) if type_hint == bool else type_hint(value)
244			except ValueError as e:
245			# ValueError: invalid literal for int() with base 10: 'nope'
246			raise TypeCoercionError(value, text_type(e))
247			else:
248			# no type hint, but we know value is a string, so try to match with the regex patterns
249			# if there's still no match, `typify_str_no_hint` will return `value`
250			return typify_str_no_hint(value)
251
252
253			def typify_data_structure(value, type_hint=None):
254			if isinstance(value, Mapping):
255			return type(value)((k, typify(v, type_hint)) for k, v in iteritems(value))
256			elif isiterable(value):
257			return type(value)(typify(v, type_hint) for v in value)
258			else:
259			return typify(value, type_hint)
260
261
262			def maybecall(value):
263			return value() if callable(value) else value
264
265
266			def listify(val, return_type=tuple):
267			"""
268			Examples:
269			>>> listify('abc', return_type=list)
270			['abc']
271			>>> listify(None)
272			()
273			>>> listify(False)
274			(False,)
275			>>> listify(('a', 'b', 'c'), return_type=list)
276			['a', 'b', 'c']
277			"""
278			# TODO: flatlistify((1, 2, 3), 4, (5, 6, 7))
279			if val is None:
280			return return_type()
281			elif isiterable(val):
282			return return_type(val)
283			else:
284			return return_type((val, ))
285

kalefranz / auxlib

boolify() F last analyzed 2017-05-18 17:16 UTC

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boolify() F
last analyzed 2017-05-18 17:16 UTC