python-barcode/barcode/codex.py at extensibility · patchwright/python-barcode · GitHub

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"""Module: barcode.codex

:Provided barcodes: Code 39, Code 128, PZN

"""

from barcode.base import Barcode

from barcode.charsets import code128

from barcode.charsets import code39

from barcode.errors import BarcodeError

from barcode.errors import IllegalCharacterError

from barcode.errors import NumberOfDigitsError

__docformat__ = "restructuredtext en"

# Sizes

MIN_SIZE = 0.2

MIN_QUIET_ZONE = 2.54

def check_code(code, name, allowed):

wrong = []

for char in code:

if char not in allowed:

wrong.append(char)

if wrong:

raise IllegalCharacterError(

"The following characters are not valid for {name}: {wrong}".format(

name=name, wrong=", ".join(wrong)

)

class Code39(Barcode):

"""A Code39 barcode implementation"""

name = "Code 39"

def __init__(self, code: str, writer=None, add_checksum: bool = True):

r"""

:param code: Code 39 string without \* and without checksum.

:param writer: A ``barcode.writer`` instance used to render the barcode

(default: SVGWriter).

:param add_checksum: Add the checksum to code or not

"""

self.code = code.upper()

if add_checksum:

self.code += self.calculate_checksum()

self.writer = writer or self.default_writer()

check_code(self.code, self.name, code39.REF)

def __str__(self):

return self.code

def get_fullcode(self) -> str:

""":returns: The full code as it will be encoded."""

return self.code

def calculate_checksum(self):

check = sum(code39.MAP[x][0] for x in self.code) % 43

for k, v in code39.MAP.items():

if check == v[0]:

return k

def build(self):

chars = [code39.EDGE]

for char in self.code:

chars.append(code39.MAP[char][1])

chars.append(code39.EDGE)

return [code39.MIDDLE.join(chars)]

def render(self, writer_options=None, text=None):

options = {"module_width": MIN_SIZE, "quiet_zone": MIN_QUIET_ZONE}

options.update(writer_options or {})

return super().render(options, text)

class PZN7(Code39):

"""Initializes new German number for pharmaceutical products.

:parameters:

pzn : String

Code to render.

writer : barcode.writer Instance

The writer to render the barcode (default: SVGWriter).

"""

name = "Pharmazentralnummer"

digits = 6

def __init__(self, pzn, writer=None):

pzn = pzn[: self.digits]

if not pzn.isdigit():

raise IllegalCharacterError("PZN can only contain numbers.")

if len(pzn) != self.digits:

raise NumberOfDigitsError(

"PZN must have {} digits, not {}.".format(self.digits, len(pzn))

)

self.pzn = pzn

self.pzn = "{}{}".format(pzn, self.calculate_checksum())

super().__init__("PZN-{}".format(self.pzn), writer, add_checksum=False)

def get_fullcode(self):

return "PZN-{}".format(self.pzn)

def calculate_checksum(self):

sum_ = sum(int(x) * int(y) for x, y in enumerate(self.pzn, start=2))

checksum = sum_ % 11

if checksum == 10:

raise BarcodeError("Checksum can not be 10 for PZN.")

else:

return checksum

class PZN8(PZN7):

"""Will be fully added in v0.9."""

digits = 7

class Code128(Barcode):

"""Initializes a new Code128 instance. The checksum is added automatically

when building the bars.

:parameters:

code : String

Code 128 string without checksum (added automatically).

writer : barcode.writer Instance

The writer to render the barcode (default: SVGWriter).

"""

name = "Code 128"

def __init__(self, code, writer=None):

self.code = code

self.writer = writer or self.default_writer()

self._charset = "B"

self._buffer = ""

check_code(self.code, self.name, code128.ALL)

def __str__(self):

return self.code

@property

def encoded(self):

return self._build()

def get_fullcode(self):

return self.code

def _new_charset(self, which):

if which == "A":

code = self._convert("TO_A")

elif which == "B":

code = self._convert("TO_B")

elif which == "C":

code = self._convert("TO_C")

self._charset = which

return [code]

def _maybe_switch_charset(self, pos):

char = self.code[pos]

next_ = self.code[pos : pos + 10]

def look_next():

digits = 0

for c in next_:

if c.isdigit():

digits += 1

else:

break

return digits > 3 and (digits % 2) == 0

codes = []

if self._charset == "C" and not char.isdigit():

if char in code128.B:

codes = self._new_charset("B")

elif char in code128.A:

codes = self._new_charset("A")

if len(self._buffer) == 1:

codes.append(self._convert(self._buffer[0]))

self._buffer = ""

elif self._charset == "B":

if look_next():

codes = self._new_charset("C")

elif char not in code128.B:

if char in code128.A:

codes = self._new_charset("A")

elif self._charset == "A":

if look_next():

codes = self._new_charset("C")

elif char not in code128.A:

if char in code128.B:

codes = self._new_charset("B")

return codes

def _convert(self, char):

if self._charset == "A":

return code128.A[char]

elif self._charset == "B":

return code128.B[char]

elif self._charset == "C":

if char in code128.C:

return code128.C[char]

elif char.isdigit():

self._buffer += char

if len(self._buffer) == 2:

value = int(self._buffer)

self._buffer = ""

return value

def _try_to_optimize(self, encoded):

if encoded[1] in code128.TO:

encoded[:2] = [code128.TO[encoded[1]]]

return encoded

def _calculate_checksum(self, encoded):

cs = [encoded[0]]

for i, code_num in enumerate(encoded[1:], start=1):

cs.append(i * code_num)

return sum(cs) % 103

def _build(self):

encoded = [code128.START_CODES[self._charset]]

for i, char in enumerate(self.code):

encoded.extend(self._maybe_switch_charset(i))

code_num = self._convert(char)

if code_num is not None:

encoded.append(code_num)

# Finally look in the buffer

if len(self._buffer) == 1:

encoded.extend(self._new_charset("B"))

encoded.append(self._convert(self._buffer[0]))

self._buffer = ""

encoded = self._try_to_optimize(encoded)

return encoded

def build(self):

encoded = self._build()

encoded.append(self._calculate_checksum(encoded))

code = ""

for code_num in encoded:

code += code128.CODES[code_num]

code += code128.STOP

code += "11"

return [code]

def render(self, writer_options=None, text=None):

options = {"module_width": MIN_SIZE, "quiet_zone": MIN_QUIET_ZONE}

options.update(writer_options or {})

return super().render(options, text)

class Gs1_128(Code128):

"""

following the norm, a gs1-128 barcode is a subset of code 128 barcode,

it can be generated by prepending the code with the FNC1 character

https://en.wikipedia.org/wiki/GS1-128

https://www.gs1-128.info/

"""

name = "GS1-128"

FNC1_CHAR = "\xf1"

def __init__(self, code, writer=None):

code = self.FNC1_CHAR + code

super().__init__(code, writer)

def get_fullcode(self):

return super().get_fullcode()[1:]

# For pre 0.8 compatibility

PZN = PZN7

python-barcode/barcode/codex.py at extensibility · patchwright/python-barcode · GitHub

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