Coverage for /var/srv/projects/api.amasfac.comuna18.com/tmp/venv/lib/python3.9/site-packages/faker/providers/barcode/en_US/__init__.py: 18%
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« prev ^ index » next coverage.py v6.4.4, created at 2023-07-17 14:22 -0600
1import re
3from itertools import product
4from typing import Dict, Optional, Pattern
6from .. import PrefixType
7from .. import Provider as BarcodeProvider
10class Provider(BarcodeProvider):
11 """Implement barcode provider for ``en_US`` locale.
13 Sources:
15 - https://gs1.org/standards/id-keys/company-prefix
16 """
18 local_prefixes = (
19 *product((0,), range(10)),
20 *product((1,), range(4)),
21 )
23 upc_e_base_pattern: Pattern = re.compile(r"^\d{6}$")
24 upc_ae_pattern1: Pattern = re.compile(
25 r"^(?P<number_system_digit>[01])" # The first digit must be 0 or 1
26 r"(?=\d{11}$)" # followed by 11 digits of which
27 r"(?P<mfr_code>\d{2})" # the first 2 digits make up the manufacturer code,
28 r"(?:(?P<extra>[012])0{4})" # if immediately followed by 00000, 10000, or 20000,
29 r"(?P<product_code>\d{3})" # a 3-digit product code,
30 r"(?P<check_digit>\d)$", # and finally a check digit.
31 )
32 upc_ae_pattern2: Pattern = re.compile(
33 r"^(?P<number_system_digit>[01])" # The first digit must be 0 or 1
34 r"(?=\d{11}$)" # followed by 11 digits of which
35 r"(?P<mfr_code>\d{3,4}?)" # the first 3 or 4 digits make up the manufacturer code,
36 r"(?:0{5})" # if immediately followed by 00000,
37 r"(?P<product_code>\d{1,2})" # a 2-digit or single digit product code,
38 r"(?P<check_digit>\d)$", # and finally a check digit.
39 )
40 upc_ae_pattern3: Pattern = re.compile(
41 r"^(?P<number_system_digit>[01])" # The first digit must be 0 or 1
42 r"(?=\d{11}$)" # followed by 11 digits of which
43 r"(?P<mfr_code>\d{5})" # the first 5 digits make up the manufacturer code,
44 r"(?:0{4}(?P<extra>[5-9]))" # if immediately followed by 0000 and a 5, 6, 7, 8, or 9,
45 r"(?P<check_digit>\d)$", # and finally a check digit.
46 )
48 def ean13(self, prefixes: PrefixType = (), leading_zero: Optional[bool] = None) -> str:
49 """Generate an EAN-13 barcode.
51 If ``leading_zero`` is ``True``, the leftmost digit of the barcode will
52 be set to ``0``. If ``False``, the leftmost digit cannot be ``0``. If
53 ``None`` (default), the leftmost digit can be any digit.
55 If a value for ``prefixes`` is specified, the result will begin with one
56 of the sequences in ``prefixes`` and will ignore ``leading_zero``.
58 This method uses the standard barcode provider's |ean13| under the
59 hood with the ``prefixes`` argument set to the correct value to attain
60 the behavior described above.
62 .. note::
63 EAN-13 barcode that starts with a zero can be converted to UPC-A
64 by dropping the leading zero. This may cause problems with readers
65 that treat all of these code as UPC-A codes and drop the first digit
66 when reading it.
68 You can set the argument ``prefixes`` ( or ``leading_zero`` for
69 convenience) explicitly to avoid or to force the generated barcode to
70 start with a zero. You can also generate actual UPC-A barcode with
71 |EnUsBarcodeProvider.upc_a|.
73 :sample:
74 :sample: leading_zero=False
75 :sample: leading_zero=True
76 :sample: prefixes=('00',)
77 :sample: prefixes=('45', '49')
78 """
79 if not prefixes:
80 if leading_zero is True:
81 prefixes = ((0,),)
82 elif leading_zero is False:
83 prefixes = ((self.random_int(1, 9),),)
85 return super().ean13(prefixes=prefixes)
87 def _convert_upc_a2e(self, upc_a: str) -> str:
88 """Convert a 12-digit UPC-A barcode to its 8-digit UPC-E equivalent.
90 .. warning::
91 Not all UPC-A barcodes can be converted.
92 """
93 if not isinstance(upc_a, str):
94 raise TypeError("`upc_a` is not a string")
95 m1 = self.upc_ae_pattern1.match(upc_a)
96 m2 = self.upc_ae_pattern2.match(upc_a)
97 m3 = self.upc_ae_pattern3.match(upc_a)
98 if not any([m1, m2, m3]):
99 raise ValueError("`upc_a` has an invalid value")
100 upc_e_template = "{number_system_digit}{mfr_code}{product_code}{extra}{check_digit}"
101 if m1:
102 upc_e = upc_e_template.format(**m1.groupdict())
103 elif m2:
104 groupdict: Dict[str, str] = m2.groupdict()
105 mfr_code = groupdict.get("mfr_code") or ""
106 groupdict["extra"] = str(len(mfr_code))
107 upc_e = upc_e_template.format(**groupdict)
108 elif m3:
109 groupdict = m3.groupdict()
110 groupdict["product_code"] = ""
111 upc_e = upc_e_template.format(**groupdict)
112 return upc_e
114 def _upc_ae(self, base: Optional[str] = None, number_system_digit: Optional[int] = None) -> str:
115 """Create a 12-digit UPC-A barcode that can be converted to UPC-E.
117 The expected value of ``base`` is a 6-digit string. If any other value
118 is provided, this method will use a random 6-digit string instead.
120 The expected value of ``number_system_digit`` is the integer ``0`` or
121 ``1``. If any other value is provided, this method will randomly choose
122 from the two.
124 Please also view notes on |EnUsBarcodeProvider.upc_a| and
125 |EnUsBarcodeProvider.upc_e| for more details.
126 """
127 base_ = (
128 [int(x) for x in base]
129 if isinstance(base, str) and self.upc_e_base_pattern.match(base)
130 else [self.random_int(0, 9) for _ in range(6)]
131 )
132 if number_system_digit not in [0, 1]:
133 number_system_digit = self.random_int(0, 1)
135 if base_[-1] <= 2:
136 code = base_[:2] + base_[-1:] + [0] * 4 + base_[2:-1]
137 elif base_[-1] <= 4:
138 code = base_[: base_[-1]] + [0] * 5 + base_[base_[-1] : -1]
139 else:
140 code = base_[:5] + [0] * 4 + base_[-1:]
142 code.insert(0, number_system_digit)
143 weights = [3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3]
144 weighted_sum = sum(x * y for x, y in zip(code, weights))
145 check_digit = (10 - weighted_sum % 10) % 10
146 code.append(check_digit)
147 return "".join(str(x) for x in code)
149 def upc_a(
150 self,
151 upc_ae_mode: bool = False,
152 base: Optional[str] = None,
153 number_system_digit: Optional[int] = None,
154 ) -> str:
155 """Generate a 12-digit UPC-A barcode.
157 The value of ``upc_ae_mode`` controls how barcodes will be generated. If
158 ``False`` (default), barcodes are not guaranteed to have a UPC-E
159 equivalent. In this mode, the method uses |EnUsBarcodeProvider.ean13|
160 under the hood, and the values of ``base`` and ``number_system_digit``
161 will be ignored.
163 If ``upc_ae_mode`` is ``True``, the resulting barcodes are guaranteed to
164 have a UPC-E equivalent, and the values of ``base`` and
165 ``number_system_digit`` will be used to control what is generated.
167 Under this mode, ``base`` is expected to have a 6-digit string value. If
168 any other value is supplied, a random 6-digit string will be used
169 instead. As for ``number_system_digit``, the expected value is a ``0``
170 or a ``1``. If any other value is provided, this method will randomly
171 choose from the two.
173 .. important::
174 When ``upc_ae_mode`` is enabled, you might encounter instances where
175 different values of ``base`` (e.g. ``'120003'`` and ``'120004'``)
176 produce the same UPC-A barcode. This is normal, and the reason lies
177 within the whole conversion process. To learn more about this and
178 what ``base`` and ``number_system_digit`` actually represent, please
179 refer to |EnUsBarcodeProvider.upc_e|.
181 :sample:
182 :sample: upc_ae_mode=True, number_system_digit=0
183 :sample: upc_ae_mode=True, number_system_digit=1
184 :sample: upc_ae_mode=True, base='123456', number_system_digit=0
185 :sample: upc_ae_mode=True, base='120003', number_system_digit=0
186 :sample: upc_ae_mode=True, base='120004', number_system_digit=0
187 """
188 if upc_ae_mode is True:
189 return self._upc_ae(base=base, number_system_digit=number_system_digit)
190 else:
191 ean13 = self.ean13(leading_zero=True)
192 return ean13[1:]
194 def upc_e(
195 self,
196 base: Optional[str] = None,
197 number_system_digit: Optional[int] = None,
198 safe_mode: bool = True,
199 ) -> str:
200 """Generate an 8-digit UPC-E barcode.
202 UPC-E barcodes can be expressed in 6, 7, or 8-digit formats, but this
203 method uses the 8 digit format, since it is trivial to convert to the
204 other two formats. The first digit (starting from the left) is
205 controlled by ``number_system_digit``, and it can only be a ``0`` or a
206 ``1``. The last digit is the check digit that is inherited from the
207 UPC-E barcode's UPC-A equivalent. The middle six digits are collectively
208 referred to as the ``base`` (for a lack of a better term).
210 On that note, this method uses ``base`` and ``number_system_digit`` to
211 first generate a UPC-A barcode for the check digit, and what happens
212 next depends on the value of ``safe_mode``. The argument ``safe_mode``
213 exists, because there are some UPC-E values that share the same UPC-A
214 equivalent. For example, any UPC-E barcode of the form ``abc0000d``,
215 ``abc0003d``, and ``abc0004d`` share the same UPC-A value
216 ``abc00000000d``, but that UPC-A value will only convert to ``abc0000d``
217 because of (a) how UPC-E is just a zero-suppressed version of UPC-A and
218 (b) the rules around the conversion.
220 If ``safe_mode`` is ``True`` (default), this method performs another set
221 of conversions to guarantee that the UPC-E barcodes generated can be
222 converted to UPC-A, and that UPC-A barcode can be converted back to the
223 original UPC-E barcode. Using the example above, even if the bases
224 ``120003`` or ``120004`` are used, the resulting UPC-E barcode will
225 always use the base ``120000``.
227 If ``safe_mode`` is ``False``, then the ``number_system_digit``,
228 ``base``, and the computed check digit will just be concatenated
229 together to produce the UPC-E barcode, and attempting to convert the
230 barcode to UPC-A and back again to UPC-E will exhibit the behavior
231 described above.
233 :sample:
234 :sample: base='123456'
235 :sample: base='123456', number_system_digit=0
236 :sample: base='123456', number_system_digit=1
237 :sample: base='120000', number_system_digit=0
238 :sample: base='120003', number_system_digit=0
239 :sample: base='120004', number_system_digit=0
240 :sample: base='120000', number_system_digit=0, safe_mode=False
241 :sample: base='120003', number_system_digit=0, safe_mode=False
242 :sample: base='120004', number_system_digit=0, safe_mode=False
243 """
244 if safe_mode is not False:
245 upc_ae = self._upc_ae(base=base, number_system_digit=number_system_digit)
246 return self._convert_upc_a2e(upc_ae)
247 else:
248 upc_ae = self._upc_ae(base=base, number_system_digit=number_system_digit)
249 return upc_ae[0] + "".join(str(x) for x in base or "") + upc_ae[-1]