add pure_barcode option, and use it in tests

Author: dlenski

README.md

@@ -29,7 +29,7 @@ BarCode(raw='This should be QR_CODE', parsed='This should be QR_CODE', format='Q
 The attributes of the decoded `BarCode` object are `raw`, `parsed`, `format`, `type`, and `points`. The list of formats which ZXing can decode is
 [here](https://zxing.github.io/zxing/apidocs/com/google/zxing/BarcodeFormat.html).
 
-The `decode()` method accepts an image path (or list of paths) and takes optional parameters `try_harder` (boolean) and `possible_formats` (list of formats to consider).
+The `decode()` method accepts an image path (or list of paths) and takes optional parameters `try_harder` (boolean), `possible_formats` (list of formats to consider), and `pure_barcode` (boolean).
 If no barcode is found, it returns `None`, and if it encounters any other recognizable error from the Java ZXing library, it raises `BarCodeReaderException`.
 
 ## Command-line interface

test/test_all.py

@@ -32,7 +32,7 @@ def test_decoding():
     for filename, expected_format, expected_raw in test_barcodes:
         path = os.path.join(test_barcode_dir, filename)
         logging.debug('Trying to parse {}, expecting {!r}.'.format(path, expected_raw))
-        dec = test_reader.decode(path)
+        dec = test_reader.decode(path, pure_barcode=True)
         if dec.raw != expected_raw:
             raise AssertionError('Expected {!r} but got {!r}'.format(expected_raw, dec.raw))
         if dec.format != expected_format:
@@ -43,7 +43,7 @@ def test_decoding():
 def test_decoding_multiple():
     reader = zxing.BarCodeReader()
     filenames = [os.path.join(test_barcode_dir, filename) for filename, expected_format, expected_raw in test_barcodes]
-    for dec, (filename, expected_format, expected_raw) in zip(reader.decode(filenames), test_barcodes):
+    for dec, (filename, expected_format, expected_raw) in zip(reader.decode(filenames, pure_barcode=True), test_barcodes):
         if dec.raw != expected_raw:
             raise AssertionError('{}: Expected {!r} but got {!r}'.format(filename, expected_raw, dec.parsed))
         if dec.format != expected_format:
@@ -79,7 +79,7 @@ def test_possible_formats():
     for filename, expected_format, expected_raw in test_barcodes:
         path = os.path.join(test_barcode_dir, filename)
         incomplete_formats = all_test_formats - {expected_format}
-        dec = test_reader.decode(path, possible_formats=incomplete_formats)
+        dec = test_reader.decode(path, possible_formats=incomplete_formats, pure_barcode=True)
         if dec is not None:
             raise AssertionError('Tried to decode {}-format barcode with possible_formats={!r}; expected failure, but got result in {} format'.format(
                 expected_format, incomplete_formats, dec.format))

zxing/__init__.py

@@ -31,7 +31,7 @@ def __init__(self, classpath=None, java=None):
         else:
             self.classpath = os.path.join(os.path.dirname(__file__), 'java', '*')
 
-    def decode(self, filenames, try_harder=False, possible_formats=None):
+    def decode(self, filenames, try_harder=False, possible_formats=None, pure_barcode=False):
         possible_formats = (possible_formats,) if isinstance(possible_formats, str) else possible_formats
 
         if isinstance(filenames, str):
@@ -44,6 +44,8 @@ def decode(self, filenames, try_harder=False, possible_formats=None):
         cmd = [self.java, '-cp', self.classpath, self.cls] + file_uris
         if try_harder:
             cmd.append('--try_harder')
+        if pure_barcode:
+            cmd.append('--pure_barcode')
         if possible_formats:
             for pf in possible_formats:
                 cmd += ['--possible_formats', pf ]