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import re
import math
import six
from six.moves import xrange
from qrcode import base, exceptions, LUT
# QR encoding modes.
MODE_NUMBER = 1 << 0
MODE_ALPHA_NUM = 1 << 1
MODE_8BIT_BYTE = 1 << 2
MODE_KANJI = 1 << 3
# Encoding mode sizes.
MODE_SIZE_SMALL = {
MODE_NUMBER: 10,
MODE_ALPHA_NUM: 9,
MODE_8BIT_BYTE: 8,
MODE_KANJI: 8,
}
MODE_SIZE_MEDIUM = {
MODE_NUMBER: 12,
MODE_ALPHA_NUM: 11,
MODE_8BIT_BYTE: 16,
MODE_KANJI: 10,
}
MODE_SIZE_LARGE = {
MODE_NUMBER: 14,
MODE_ALPHA_NUM: 13,
MODE_8BIT_BYTE: 16,
MODE_KANJI: 12,
}
ALPHA_NUM = six.b('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:')
RE_ALPHA_NUM = re.compile(six.b('^[') + re.escape(ALPHA_NUM) + six.b(']*\Z'))
# The number of bits for numeric delimited data lengths.
NUMBER_LENGTH = {3: 10, 2: 7, 1: 4}
PATTERN_POSITION_TABLE = [
[],
[6, 18],
[6, 22],
[6, 26],
[6, 30],
[6, 34],
[6, 22, 38],
[6, 24, 42],
[6, 26, 46],
[6, 28, 50],
[6, 30, 54],
[6, 32, 58],
[6, 34, 62],
[6, 26, 46, 66],
[6, 26, 48, 70],
[6, 26, 50, 74],
[6, 30, 54, 78],
[6, 30, 56, 82],
[6, 30, 58, 86],
[6, 34, 62, 90],
[6, 28, 50, 72, 94],
[6, 26, 50, 74, 98],
[6, 30, 54, 78, 102],
[6, 28, 54, 80, 106],
[6, 32, 58, 84, 110],
[6, 30, 58, 86, 114],
[6, 34, 62, 90, 118],
[6, 26, 50, 74, 98, 122],
[6, 30, 54, 78, 102, 126],
[6, 26, 52, 78, 104, 130],
[6, 30, 56, 82, 108, 134],
[6, 34, 60, 86, 112, 138],
[6, 30, 58, 86, 114, 142],
[6, 34, 62, 90, 118, 146],
[6, 30, 54, 78, 102, 126, 150],
[6, 24, 50, 76, 102, 128, 154],
[6, 28, 54, 80, 106, 132, 158],
[6, 32, 58, 84, 110, 136, 162],
[6, 26, 54, 82, 110, 138, 166],
[6, 30, 58, 86, 114, 142, 170]
]
G15 = (
(1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) |
(1 << 0))
G18 = (
(1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) |
(1 << 2) | (1 << 0))
G15_MASK = (1 << 14) | (1 << 12) | (1 << 10) | (1 << 4) | (1 << 1)
PAD0 = 0xEC
PAD1 = 0x11
# Precompute bit count limits, indexed by error correction level and code size
_data_count = lambda block: block.data_count
BIT_LIMIT_TABLE = [
[0] + [8*sum(map(_data_count, base.rs_blocks(version, error_correction)))
for version in xrange(1, 41)]
for error_correction in xrange(4)
]
def BCH_type_info(data):
d = data << 10
while BCH_digit(d) - BCH_digit(G15) >= 0:
d ^= (G15 << (BCH_digit(d) - BCH_digit(G15)))
return ((data << 10) | d) ^ G15_MASK
def BCH_type_number(data):
d = data << 12
while BCH_digit(d) - BCH_digit(G18) >= 0:
d ^= (G18 << (BCH_digit(d) - BCH_digit(G18)))
return (data << 12) | d
def BCH_digit(data):
digit = 0
while data != 0:
digit += 1
data >>= 1
return digit
def pattern_position(version):
return PATTERN_POSITION_TABLE[version - 1]
def mask_func(pattern):
"""
Return the mask function for the given mask pattern.
"""
if pattern == 0: # 000
return lambda i, j: (i + j) % 2 == 0
if pattern == 1: # 001
return lambda i, j: i % 2 == 0
if pattern == 2: # 010
return lambda i, j: j % 3 == 0
if pattern == 3: # 011
return lambda i, j: (i + j) % 3 == 0
if pattern == 4: # 100
return lambda i, j: (math.floor(i / 2) + math.floor(j / 3)) % 2 == 0
if pattern == 5: # 101
return lambda i, j: (i * j) % 2 + (i * j) % 3 == 0
if pattern == 6: # 110
return lambda i, j: ((i * j) % 2 + (i * j) % 3) % 2 == 0
if pattern == 7: # 111
return lambda i, j: ((i * j) % 3 + (i + j) % 2) % 2 == 0
raise TypeError("Bad mask pattern: " + pattern) # pragma: no cover
def mode_sizes_for_version(version):
if version < 10:
return MODE_SIZE_SMALL
elif version < 27:
return MODE_SIZE_MEDIUM
else:
return MODE_SIZE_LARGE
def length_in_bits(mode, version):
if mode not in (
MODE_NUMBER, MODE_ALPHA_NUM, MODE_8BIT_BYTE, MODE_KANJI):
raise TypeError("Invalid mode (%s)" % mode) # pragma: no cover
if version < 1 or version > 40: # pragma: no cover
raise ValueError(
"Invalid version (was %s, expected 1 to 40)" % version)
return mode_sizes_for_version(version)[mode]
def lost_point(modules):
modules_count = len(modules)
lost_point = 0
lost_point = _lost_point_level1(modules, modules_count)
lost_point += _lost_point_level2(modules, modules_count)
lost_point += _lost_point_level3(modules, modules_count)
lost_point += _lost_point_level4(modules, modules_count)
return lost_point
def _lost_point_level1(modules, modules_count):
lost_point = 0
modules_range = xrange(modules_count)
container = [0] * (modules_count + 1)
for row in modules_range:
this_row = modules[row]
previous_color = this_row[0]
length = 0
for col in modules_range:
if this_row[col] == previous_color:
length += 1
else:
if length >= 5:
container[length] += 1
length = 1
previous_color = this_row[col]
if length >= 5:
container[length] += 1
for col in modules_range:
previous_color = modules[0][col]
length = 0
for row in modules_range:
if modules[row][col] == previous_color:
length += 1
else:
if length >= 5:
container[length] += 1
length = 1
previous_color = modules[row][col]
if length >= 5:
container[length] += 1
lost_point += sum(container[each_length] * (each_length - 2)
for each_length in xrange(5, modules_count + 1))
return lost_point
def _lost_point_level2(modules, modules_count):
lost_point = 0
modules_range = xrange(modules_count - 1)
for row in modules_range:
this_row = modules[row]
next_row = modules[row + 1]
# use iter() and next() to skip next four-block. e.g.
# d a f if top-right a != b botton-right,
# c b e then both abcd and abef won't lost any point.
modules_range_iter = iter(modules_range)
for col in modules_range_iter:
top_right = this_row[col + 1]
if top_right != next_row[col + 1]:
# reduce 33.3% of runtime via next().
# None: raise nothing if there is no next item.
next(modules_range_iter, None)
elif top_right != this_row[col]:
continue
elif top_right != next_row[col]:
continue
else:
lost_point += 3
return lost_point
def _lost_point_level3(modules, modules_count):
# 1 : 1 : 3 : 1 : 1 ratio (dark:light:dark:light:dark) pattern in
# row/column, preceded or followed by light area 4 modules wide. From ISOIEC.
# pattern1: 10111010000
# pattern2: 00001011101
modules_range = xrange(modules_count)
modules_range_short = xrange(modules_count-10)
lost_point = 0
for row in modules_range:
this_row = modules[row]
modules_range_short_iter = iter(modules_range_short)
col = 0
for col in modules_range_short_iter:
if (
not this_row[col + 1]
and this_row[col + 4]
and not this_row[col + 5]
and this_row[col + 6]
and not this_row[col + 9]
and (
this_row[col + 0]
and this_row[col + 2]
and this_row[col + 3]
and not this_row[col + 7]
and not this_row[col + 8]
and not this_row[col + 10]
or
not this_row[col + 0]
and not this_row[col + 2]
and not this_row[col + 3]
and this_row[col + 7]
and this_row[col + 8]
and this_row[col + 10]
)
):
lost_point += 40
# horspool algorithm.
# if this_row[col + 10] == True, pattern1 shift 4, pattern2 shift 2. So min=2.
# if this_row[col + 10] == False, pattern1 shift 1, pattern2 shift 1. So min=1.
if this_row[col + 10]:
next(modules_range_short_iter, None)
for col in modules_range:
modules_range_short_iter = iter(modules_range_short)
row = 0
for row in modules_range_short_iter:
if (
not modules[row + 1][col]
and modules[row + 4][col]
and not modules[row + 5][col]
and modules[row + 6][col]
and not modules[row + 9][col]
and (
modules[row + 0][col]
and modules[row + 2][col]
and modules[row + 3][col]
and not modules[row + 7][col]
and not modules[row + 8][col]
and not modules[row + 10][col]
or
not modules[row + 0][col]
and not modules[row + 2][col]
and not modules[row + 3][col]
and modules[row + 7][col]
and modules[row + 8][col]
and modules[row + 10][col]
)
):
lost_point += 40
if modules[row + 10][col]:
next(modules_range_short_iter, None)
return lost_point
def _lost_point_level4(modules, modules_count):
dark_count = sum(map(sum, modules))
percent = float(dark_count) / (modules_count**2)
# Every 5% departure from 50%, rating++
rating = int(abs(percent * 100 - 50) / 5)
return rating * 10
def optimal_data_chunks(data, minimum=4):
"""
An iterator returning QRData chunks optimized to the data content.
:param minimum: The minimum number of bytes in a row to split as a chunk.
"""
data = to_bytestring(data)
re_repeat = (
six.b('{') + six.text_type(minimum).encode('ascii') + six.b(',}'))
num_pattern = re.compile(six.b('\d') + re_repeat)
num_bits = _optimal_split(data, num_pattern)
alpha_pattern = re.compile(
six.b('[') + re.escape(ALPHA_NUM) + six.b(']') + re_repeat)
for is_num, chunk in num_bits:
if is_num:
yield QRData(chunk, mode=MODE_NUMBER, check_data=False)
else:
for is_alpha, sub_chunk in _optimal_split(chunk, alpha_pattern):
if is_alpha:
mode = MODE_ALPHA_NUM
else:
mode = MODE_8BIT_BYTE
yield QRData(sub_chunk, mode=mode, check_data=False)
def _optimal_split(data, pattern):
while data:
match = re.search(pattern, data)
if not match:
break
start, end = match.start(), match.end()
if start:
yield False, data[:start]
yield True, data[start:end]
data = data[end:]
if data:
yield False, data
def to_bytestring(data):
"""
Convert data to a (utf-8 encoded) byte-string if it isn't a byte-string
already.
"""
if not isinstance(data, six.binary_type):
data = six.text_type(data).encode('utf-8')
return data
def optimal_mode(data):
"""
Calculate the optimal mode for this chunk of data.
"""
if data.isdigit():
return MODE_NUMBER
if RE_ALPHA_NUM.match(data):
return MODE_ALPHA_NUM
return MODE_8BIT_BYTE
class QRData:
"""
Data held in a QR compatible format.
Doesn't currently handle KANJI.
"""
def __init__(self, data, mode=None, check_data=True):
"""
If ``mode`` isn't provided, the most compact QR data type possible is
chosen.
"""
if check_data:
data = to_bytestring(data)
if mode is None:
self.mode = optimal_mode(data)
else:
self.mode = mode
if mode not in (MODE_NUMBER, MODE_ALPHA_NUM, MODE_8BIT_BYTE):
raise TypeError("Invalid mode (%s)" % mode) # pragma: no cover
if check_data and mode < optimal_mode(data): # pragma: no cover
raise ValueError(
"Provided data can not be represented in mode "
"{0}".format(mode))
self.data = data
def __len__(self):
return len(self.data)
def write(self, buffer):
if self.mode == MODE_NUMBER:
for i in xrange(0, len(self.data), 3):
chars = self.data[i:i + 3]
bit_length = NUMBER_LENGTH[len(chars)]
buffer.put(int(chars), bit_length)
elif self.mode == MODE_ALPHA_NUM:
for i in xrange(0, len(self.data), 2):
chars = self.data[i:i + 2]
if len(chars) > 1:
buffer.put(
ALPHA_NUM.find(chars[0]) * 45 +
ALPHA_NUM.find(chars[1]), 11)
else:
buffer.put(ALPHA_NUM.find(chars), 6)
else:
if six.PY3:
# Iterating a bytestring in Python 3 returns an integer,
# no need to ord().
data = self.data
else:
data = [ord(c) for c in self.data]
for c in data:
buffer.put(c, 8)
def __repr__(self):
return repr(self.data)
class BitBuffer:
def __init__(self):
self.buffer = []
self.length = 0
def __repr__(self):
return ".".join([str(n) for n in self.buffer])
def get(self, index):
buf_index = math.floor(index / 8)
return ((self.buffer[buf_index] >> (7 - index % 8)) & 1) == 1
def put(self, num, length):
for i in range(length):
self.put_bit(((num >> (length - i - 1)) & 1) == 1)
def __len__(self):
return self.length
def put_bit(self, bit):
buf_index = self.length // 8
if len(self.buffer) <= buf_index:
self.buffer.append(0)
if bit:
self.buffer[buf_index] |= (0x80 >> (self.length % 8))
self.length += 1
def create_bytes(buffer, rs_blocks):
offset = 0
maxDcCount = 0
maxEcCount = 0
dcdata = [0] * len(rs_blocks)
ecdata = [0] * len(rs_blocks)
for r in range(len(rs_blocks)):
dcCount = rs_blocks[r].data_count
ecCount = rs_blocks[r].total_count - dcCount
maxDcCount = max(maxDcCount, dcCount)
maxEcCount = max(maxEcCount, ecCount)
dcdata[r] = [0] * dcCount
for i in range(len(dcdata[r])):
dcdata[r][i] = 0xff & buffer.buffer[i + offset]
offset += dcCount
# Get error correction polynomial.
if ecCount in LUT.rsPoly_LUT:
rsPoly = base.Polynomial(LUT.rsPoly_LUT[ecCount], 0)
else:
rsPoly = base.Polynomial([1], 0)
for i in range(ecCount):
rsPoly = rsPoly * base.Polynomial([1, base.gexp(i)], 0)
rawPoly = base.Polynomial(dcdata[r], len(rsPoly) - 1)
modPoly = rawPoly % rsPoly
ecdata[r] = [0] * (len(rsPoly) - 1)
for i in range(len(ecdata[r])):
modIndex = i + len(modPoly) - len(ecdata[r])
if (modIndex >= 0):
ecdata[r][i] = modPoly[modIndex]
else:
ecdata[r][i] = 0
totalCodeCount = 0
for rs_block in rs_blocks:
totalCodeCount += rs_block.total_count
data = [None] * totalCodeCount
index = 0
for i in range(maxDcCount):
for r in range(len(rs_blocks)):
if i < len(dcdata[r]):
data[index] = dcdata[r][i]
index += 1
for i in range(maxEcCount):
for r in range(len(rs_blocks)):
if i < len(ecdata[r]):
data[index] = ecdata[r][i]
index += 1
return data
def create_data(version, error_correction, data_list):
buffer = BitBuffer()
for data in data_list:
buffer.put(data.mode, 4)
buffer.put(len(data), length_in_bits(data.mode, version))
data.write(buffer)
# Calculate the maximum number of bits for the given version.
rs_blocks = base.rs_blocks(version, error_correction)
bit_limit = 0
for block in rs_blocks:
bit_limit += block.data_count * 8
if len(buffer) > bit_limit:
raise exceptions.DataOverflowError(
"Code length overflow. Data size (%s) > size available (%s)" %
(len(buffer), bit_limit))
# Terminate the bits (add up to four 0s).
for i in range(min(bit_limit - len(buffer), 4)):
buffer.put_bit(False)
# Delimit the string into 8-bit words, padding with 0s if necessary.
delimit = len(buffer) % 8
if delimit:
for i in range(8 - delimit):
buffer.put_bit(False)
# Add special alternating padding bitstrings until buffer is full.
bytes_to_fill = (bit_limit - len(buffer)) // 8
for i in range(bytes_to_fill):
if i % 2 == 0:
buffer.put(PAD0, 8)
else:
buffer.put(PAD1, 8)
return create_bytes(buffer, rs_blocks)