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"""Module: barcode.upc
:Provided barcodes: UPC-A
"""
__docformat__ = "restructuredtext en"
from functools import reduce
from barcode.base import Barcode
from barcode.charsets import upc as _upc
from barcode.errors import IllegalCharacterError
from barcode.errors import NumberOfDigitsError
class UniversalProductCodeA(Barcode):
"""Universal Product Code (UPC) barcode.
UPC-A consists of 12 numeric digits.
"""
name = "UPC-A"
digits = 11
def __init__(self, upc, writer=None, make_ean=False) -> None:
"""Initializes new UPC-A barcode.
:param str upc: The upc number as string.
:param writer: barcode.writer instance. The writer to render the
barcode (default: SVGWriter).
:param bool make_ean: Indicates if a leading zero should be added to
the barcode. This converts the UPC into a valid European Article
Number (EAN).
"""
self.ean = make_ean
upc = upc[: self.digits]
if not upc.isdigit():
raise IllegalCharacterError("UPC code can only contain numbers.")
if len(upc) != self.digits:
raise NumberOfDigitsError(
f"UPC must have {self.digits} digits, not {len(upc)}."
)
self.upc = upc
self.upc = f"{upc}{self.calculate_checksum()}"
self.writer = writer or self.default_writer()
def __str__(self) -> str:
if self.ean:
return "0" + self.upc
return self.upc
def get_fullcode(self):
if self.ean:
return "0" + self.upc
return self.upc
def calculate_checksum(self):
"""Calculates the checksum for UPCA/UPC codes
:return: The checksum for 'self.upc'
:rtype: int
"""
def sum_(x, y):
return int(x) + int(y)
upc = self.upc[0 : self.digits]
oddsum = reduce(sum_, upc[::2])
evensum = reduce(sum_, upc[1::2])
check = (evensum + oddsum * 3) % 10
if check == 0:
return 0
return 10 - check
def build(self):
"""Builds the barcode pattern from 'self.upc'
:return: The pattern as string
:rtype: str
"""
code = _upc.EDGE[:]
for _i, number in enumerate(self.upc[0:6]):
code += _upc.CODES["L"][int(number)]
code += _upc.MIDDLE
for number in self.upc[6:]:
code += _upc.CODES["R"][int(number)]
code += _upc.EDGE
return [code]
def to_ascii(self):
"""Returns an ascii representation of the barcode.
:rtype: str
"""
code = self.build()
for i, line in enumerate(code):
code[i] = line.replace("1", "|").replace("0", "_")
return "\n".join(code)
def render(self, writer_options=None, text=None):
options = {"module_width": 0.33}
options.update(writer_options or {})
return super().render(options, text)
UPCA = UniversalProductCodeA
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