Merge pull request #18 from nickmaccarthy/issue_16

Support for epoch as input

Author: nickmaccarthy

README.md

@@ -84,6 +84,10 @@ By default datemath return an arrow date object representing your timestamp.
 <Arrow [2016-01-01T23:59:00+00:00]>
 >>> dm('now/d')
 <Arrow [2016-01-01T00:00:00+00:00]>
+>>> dm(1451610061) # Timestamp in epoch/unix as int (Please note, we do not support epoch millisecond at this time.  Please convert your epoch millis to the nearest second. i.e. 1451610061000/1000)
+<Arrow [2016-01-01T01:01:01+00:00]>
+>>> dm('1451610061') # Timestamp in epoch/unix as string
+<Arrow [2013-05-07T04:24:24+00:00]>
 ```
 
 If you would rather have a string, you can use arrow's ```.format()``` method.

datemath/helpers.py

@@ -107,6 +107,13 @@ def parse(expression, now=None, tz='UTC', type=None, roundDown=True):
             return getattr(now, type)
         else:
             return now
+    elif re.match('\d{10,}', str(expression)):
+        if debug: print('found an epoch timestamp')
+        if len(str(expression)) == 13:
+            raise DateMathException('Unable to parse epoch timestamps in millis, please convert to the nearest second to continue - i.e. 1451610061 / 1000')
+        ts = arrow.get(int(expression))
+        ts = ts.replace(tzinfo=tz)
+        return ts
     elif expression.startswith('now'):
         ''' parse our standard "now+1d" kind of queries '''
         math = expression[3:]

tests.py

@@ -127,6 +127,15 @@ def testParse(self):
         self.assertEqual(dm('now-2.5h').format(iso8601), arrow.utcnow().shift(hours=-2.5).format(iso8601))
         self.assertEqual(dm('now-2.5d').format(iso8601), arrow.utcnow().shift(days=-2.5).format(iso8601))
 
+        # Test epoch timestamps
+        self.assertEqual(dm('1451610061').format(iso8601), '2016-01-01T01:01:01+00:00')
+        self.assertEqual(dm(1367900664).format(iso8601), '2013-05-07T04:24:24+00:00')
+
+        self.assertRaises(DateMathException, dm, '1451610061000')
+        try:
+            dm(1451610061000)
+        except DateMathException as e:
+            self.assertTrue('Unable to parse epoch timestamps in millis' in str(e))
 
         # Catch invalid timeunits
         self.assertRaises(DateMathException, dm, '+1,')