Improved price extraction

The prices are now handled using regexp, strings and loops instead of only regex
which was inaccurate in some cases.

Added test cases.

Removed unnecessary regexp part

Fixes scrapinghub/portia#212

Author: hackrush01

scrapely/extractors.py

@@ -16,8 +16,7 @@
 _NUMERIC_ENTITIES = re.compile("&#([0-9]+)(?:;|\s)", re.U)
 _PRICE_NUMBER_RE = re.compile('(?:^|[^a-zA-Z0-9])(\d+(?:\.\d+)?)(?:$|[^a-zA-Z0-9])')
 _NUMBER_RE = re.compile('(-?\d+(?:\.\d+)?)')
-_DECIMAL_RE = re.compile(r'(\d[\d\,]*(?:(?:\.\d+)|(?:)))', re.U | re.M)
-_VALPARTS_RE = re.compile("([\.,]?\d+)")
+_DECIMAL_RE = re.compile(r'(-?\d[\d\,\.]*)', re.U | re.M)
 
 _IMAGES = (
     'mng', 'pct', 'bmp', 'gif', 'jpg', 'jpeg', 'png', 'pst', 'psp', 'tif',
@@ -273,7 +272,7 @@ def extract_number(txt):
 
     It will handle unescaped entities:
     >>> extract_number(u'£129.99')
-    u'129.99'
+    '129.99'
     """
     txt = _NUMERIC_ENTITIES.sub(lambda m: unichr(int(m.groups()[0])), txt)
     numbers = _NUMBER_RE.findall(txt)
@@ -295,22 +294,59 @@ def extract_price(txt):
     '2234'
     >>> extract_price('947')
     '947'
+    >>> extract_price('-200,069,000,006.565456')
+    '-200069000006.565456'
+    >>> extract_price('1,000,000')
+    '1000000'
+    >>> extract_price('1,000,000.00')
+    '1000000.00'
+    >>> extract_price('1,000')
+    '1000'
+    >>> extract_price('1000,00')
+    '1000.00'
+    >>> extract_price('1,000.00')
+    '1000.00'
+    >>> extract_price('500,000.00')
+    '500000.00'
+    >>> extract_price('500.000,00')
+    '500000.00'
+    >>> extract_price('-500,000.00')
+    '-500000.00'
+    >>> extract_price('500 000,00')
+    '500000.00'
+    >>> extract_price(u'£129.99')
+    '129.99'
     >>> extract_price('adsfg')
     >>> extract_price('stained, linseed oil finish, clear glas doors')
     >>> extract_price('')
-    >>> extract_price(u'£129.99')
-    u'129.99'
     """
     txt = _NUMERIC_ENTITIES.sub(lambda m: unichr(int(m.groups()[0])), txt)
+    txt = txt.replace(' ', '')
     m = _DECIMAL_RE.search(txt)
+    POINT, COMMA = 0, 1
+    decimal_separator = POINT
+
     if m:
         value = m.group(1)
-        parts = _VALPARTS_RE.findall(value)
-        decimalpart = parts.pop(-1)
-        if decimalpart[0] == "," and len(decimalpart) <= 3:
-            decimalpart = decimalpart.replace(",", ".")
-        value = "".join(parts + [decimalpart]).replace(",", "")
-        return value
+        last_point_idx = value.rfind('.')
+        last_comma_idx = value.rfind(',')
+
+        # If a number has both separators take the last one
+        if last_point_idx > 0 and last_comma_idx > 0:
+            if last_comma_idx > last_point_idx:
+                decimal_separator = COMMA
+        # If a number has only commas check the last one
+        elif last_comma_idx > 0:
+            first_comma_idx = value.find(',')
+            if (first_comma_idx == last_comma_idx and
+                    len(value) - last_comma_idx <= 3):
+                decimal_separator = COMMA
+
+        if decimal_separator == POINT:
+            value = value.replace(',', '')
+        else:
+            value = value.replace('.', '')
+        return value.replace(',', '.')
 
 
 def url(txt):