Add upc charset

remove upc dependence on ean

Author: loran425

barcode/charsets/upc.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+
+from __future__ import unicode_literals
+
+
+EDGE = '101'
+MIDDLE = '01010'
+CODES = {
+    'L': ('0001101', '0011001', '0010011', '0111101', '0100011',
+          '0110001', '0101111', '0111011', '0110111', '0001011'),
+    'R': ('1110010', '1100110', '1101100', '1000010', '1011100',
+          '1001110', '1010000', '1000100', '1001000', '1110100')
+}

barcode/upc.py

@@ -8,37 +8,95 @@
 """
 __docformat__ = 'restructuredtext en'
 
-from barcode.ean import EuropeanArticleNumber13
+from barcode.base import Barcode
+from barcode.charsets import upc as _upc
+from barcode.errors import *
 
-
-class UniversalProductCodeA(EuropeanArticleNumber13):
-    """Initializes new UPC-A barcode. Can be rendered as EAN-13 by passing
-    `True` to the `make_ean` argument.
+class UniversalProductCodeA(Barcode):
+    """Initializes new UPC-A barcode.
 
     :parameters:
         upc : String
             The upc number as string.
         writer : barcode.writer Instance
             The writer to render the barcode (default: SVGWriter).
-        make_ean : Boolean
-            Render barcode as EAN-13 with leading 0 (default: False).
     """
 
     name = 'UPC-A'
 
     digits = 11
 
-    def __init__(self, upc, writer=None, make_ean=False):
-        if make_ean:
-            UniversalProductCodeA.digits = 12
-            upc = '0' + upc
+    def __init__(self, upc, writer=None):
+        upc = upc[:self.digits]
+        if not upc.isdigit():
+            raise IllegalCharacterError('UPC code can only contain numbers.')
+        if len(upc) != self.digits:
+            raise NumberOfDigitsError('UPC must have {0} digits, not '
+                                      '{1}.'.format(self.digits, len(upc)))
         self.upc = upc
-        EuropeanArticleNumber13.__init__(self, upc, writer)
+        self.upc = '{}{}'.format(upc, self.calculate_checksum())
+        self.writer = writer or Barcode.default_writer()
 
     def __unicode__(self):
         return self.upc
 
     __str__ = __unicode__
 
+    def get_fullcode(self):
+        return self.upc
+
+    def calculate_checksum(self):
+        """Calculates the checksum for UPCA/UPC codes
+
+        :return: The checksum for 'self.upc'
+        :rtype: Integer
+        """
+        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
+        else:
+            return 10 - check
+
+
+    def build(self):
+        """Builds the barcode pattern from 'self.upc'
+
+        :return: The pattern as string
+        :rtype: String
+        """
+        print self.upc
+        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: String
+        """
+
+        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):
+        options = dict(module_width=0.33)
+        options.update(writer_options or {})
+        return Barcode.render(self, options)
 
 UPCA = UniversalProductCodeA