Merge pull request #34 from NaturalHistoryMuseum/feature/33-decode_ba…

…rcodes-csv-error

Feature/33 decode barcodes csv error

CHANGELOG.md

@@ -1,3 +1,6 @@
+# v0.1.12
+- #33 decode_barcodes csv error
+
 # v0.1.11
 - #31 Universal wheel
 

README.md

@@ -9,16 +9,17 @@ A python package for decoding barcodes, possibly more than one, in complex
 images such as scans of museum specimens.
 
 Gouda supports Python 2.7, 3.4 and 3.5. A universal wheel build is available
-on the Releases page.
+on the [releases](releases) pages.
 
 A command-line program `decode_barcodes` is available for Windows 64-bit and
 Mac OS X. It reads barcode values in individual images and in batches of images
-files in a directory. It can print values to CSV and can renaming files with
-the value(s) or barcode(s). Download from the Releases tab. For information run
+files in a directory. It can print values to CSV and can rename files with
+the value(s) or barcode(s). Download from the [releases](releases) page.
+For help run
 
     decode_barcodes --help
 
-See also the [`decode_barcodes` examples](#decode_barcodes-examples) below.
+See also the [examples](#decode_barcodes-script) below.
 
 ## `gouda/engines`
 An engine is an interface to a barcode reading library.

gouda/__init__.py

@@ -1 +1 @@
-__version__ = '0.1.11'
+__version__ = '0.1.12'

gouda/scripts/decode_barcodes.py

@@ -79,8 +79,8 @@ def result(self, path, result):
 class CSVReportVisitor(object):
     """Writes a CSV report
     """
-    def __init__(self, engine, greyscale, file=sys.stdout):
-        self.w = csv.writer(file, lineterminator='\n')
+    def __init__(self, engine, greyscale, file=None):
+        self.w = csv.writer(file if file else sys.stdout, lineterminator='\n')
         self.w.writerow([
             'OS', 'Engine', 'Directory', 'File', 'Image.conversion',
             'Elapsed', 'N.found', 'Types', 'Values', 'Strategy'
@@ -92,7 +92,12 @@ def __init__(self, engine, greyscale, file=sys.stdout):
     def result(self, path, result):
         strategy, barcodes = result
         types = '|'.join(b.type for b in barcodes)
-        values = '|'.join(b.data for b in barcodes)
+        # data could be either str or bytes
+        values = '|'.join(
+            b.data.decode() if hasattr(b.data, 'decode') else b.data
+            for b in barcodes
+        )
+
         self.w.writerow([sys.platform,
                          self.engine,
                          path.parent.name,

gouda/tests/test_decode_barcodes.py

@@ -1,19 +1,66 @@
+import os
 import unittest
 import shutil
+import sys
 
 from pathlib import Path
+from contextlib import contextmanager
+
+try:
+    from cStringIO import StringIO
+except ImportError:
+    from io import StringIO
+
 
 from gouda.engines import ZbarEngine
 from gouda.scripts.decode_barcodes import main
 
 from .utils import temp_directory_with_files
 
 
+
+@contextmanager
+def capture_stdout():
+    sys.stdout, old_stdout = StringIO(), sys.stdout
+    try:
+        yield sys.stdout
+    finally:
+        sys.stdout = old_stdout
+
+
 TESTDATA = Path(__file__).parent.joinpath('test_data')
 
 
 @unittest.skipUnless(ZbarEngine.available(), 'ZbarEngine unavailable')
 class TestRename(unittest.TestCase):
+    def test_csv(self):
+        "CSV report is printed"
+        with capture_stdout() as stdout:
+            main([
+                'zbar',
+                '--action=csv',
+                str(TESTDATA.joinpath('code128.png')),
+                str(TESTDATA.joinpath('BM001128287.jpg'))
+            ])
+        from pprint import pprint
+
+        lines = stdout.getvalue().strip().split(os.linesep)
+        self.assertEqual(3, len(lines))
+
+        header = (
+            'OS,Engine,Directory,File,Image.conversion,Elapsed,N.found,Types,'
+            'Values,Strategy'
+        )
+        self.assertEqual(header, lines[0])
+
+        self.assertIn('BM001128287.jpg', lines[1])
+        self.assertIn('CODE128|CODE128|CODE128', lines[1])
+        self.assertIn('BM001128287|BM001128286|BM001128288', lines[1])
+
+        self.assertIn('code128.png', lines[2])
+        self.assertIn('CODE128', lines[2])
+        self.assertIn('Stegosaurus', lines[2])
+
     def test_rename(self):
         "File is renamed with value of barcode"
         with temp_directory_with_files(TESTDATA.joinpath('code128.png')) as tempdir: