created csv iterator to replace CSVParser iteration facilities

--HG--
extra : convert_revision : svn%3Ab85faa78-f9eb-468e-a121-7cced6da292c%40319

scrapy/trunk/scrapy/utils/iterators.py

@@ -0,0 +1,23 @@
+import csv
+
+from scrapy.http import Response
+from scrapy import log
+
+def csv_iter(response, delimiter=None, headers=None):
+    if delimiter:
+        csv_r = csv.reader(response.body.to_unicode().split('\n'), delimiter=delimiter)
+    else:
+        csv_r = csv.reader(response.body.to_unicode().split('\n'))
+
+    if not headers:
+        headers = csv_r.next()
+
+    while True:
+        node = csv_r.next()
+
+        if len(node) != len(headers):
+            log.msg("ignoring node %d (length: %d, should be: %d)" % (csv_r.line_num, len(node), len(headers)), log.WARNING)
+            continue
+
+        yield dict(zip(headers, node))
+