Added support for parsing out the timestamp

The timestamp is in the LOG module, at an offset of either 465 or
469. There is no obvious marker for which files have it at 465 and
which at 469.

BioLogic.py

@@ -7,7 +7,7 @@ import re
 import csv
 from os import SEEK_SET, SEEK_CUR
 import time
-from datetime import date
+from datetime import date, datetime, timedelta
 from collections import OrderedDict
 from warnings import warn
 
@@ -261,3 +261,24 @@ class MPRfile:
             tm = time.strptime(str(log_module['date'],  encoding='ascii'),
                                '%m/%d/%y')
             self.enddate = date(tm.tm_year, tm.tm_mon, tm.tm_mday)
+
+            ## There is a timestamp at either 465 or 469 bytes
+            ## I can't find any reason why it is one or the other in any
+            ## given file
+            ole_timestamp1 = np.fromstring(log_module['data'][465:],
+                                           dtype='<f8', count=1)
+            ole_timestamp2 = np.fromstring(log_module['data'][469:],
+                                           dtype='<f8', count=1)
+            if ole_timestamp1 > 40000 and ole_timestamp1 < 50000:
+                ole_timestamp = ole_timestamp1
+            elif ole_timestamp2 > 40000 and ole_timestamp2 < 50000:
+                ole_timestamp = ole_timestamp2
+
+            ole_base = datetime(1899, 12, 30, tzinfo=None)
+            ole_timedelta = timedelta(days=ole_timestamp[0])
+            self.timestamp = ole_base + ole_timedelta
+            if self.startdate != self.timestamp.date():
+                raise ValueError("""Date mismatch:
+                Start date: %s
+                End date: %s
+                Timestamp: %s""" % (self.startdate, self.enddate, self.timestamp))

tests/test_BioLogic.py

@@ -2,7 +2,7 @@
 
 import os.path
 import re
-from datetime import date
+from datetime import date, datetime
 
 import numpy as np
 from numpy.testing import assert_array_almost_equal, assert_array_equal
@@ -89,7 +89,17 @@ def test_open_MPR_fails_for_bad_file():
     mpr1 = MPRfile(os.path.join(testdata_dir, 'arbin1.res'))
 
 
-def assert_MPR_matches_MPT(mpr, mpt):
+def timestamp_from_comments(comments):
+    for line in comments:
+        time_match = re.match(b'Acquisition started on : ([0-9/]+ [0-9:]+)', line)
+        if time_match:
+            timestamp = datetime.strptime(str(time_match.group(1), encoding='ascii'),
+                                          '%m/%d/%Y %H:%M:%S')
+            return timestamp
+    raise AttributeError("No timestamp in comments")
+
+
+def assert_MPR_matches_MPT(mpr, mpt, comments):
 
     def assert_field_matches(fieldname, decimal):
         if fieldname in mpr.dtype.fields:
@@ -133,17 +143,23 @@ def assert_MPR_matches_MPT(mpr, mpt):
     assert_field_exact("cycle number")
     assert_field_matches("(Q-Qo)/C", decimal=6)  # 32 bit float precision
     
+    try:
+        eq_(timestamp_from_comments(comments), mpr.timestamp)
+    except AttributeError:
+        pass
+    
+
 
 def test_MPR1_matches_MPT1():
     mpr1 = MPRfile(os.path.join(testdata_dir, 'bio-logic1.mpr'))
     mpt1, comments = MPTfile(os.path.join(testdata_dir, 'bio-logic1.mpt'))
-    assert_MPR_matches_MPT(mpr1, mpt1)
+    assert_MPR_matches_MPT(mpr1, mpt1, comments)
 
 
 def test_MPR2_matches_MPT2():
     mpr2 = MPRfile(os.path.join(testdata_dir, 'bio-logic2.mpr'))
     mpt2, comments = MPTfile(os.path.join(testdata_dir, 'bio-logic2.mpt'))
-    assert_MPR_matches_MPT(mpr2, mpt2)
+    assert_MPR_matches_MPT(mpr2, mpt2, comments)
 
 
 ## No bio-logic3.mpt file
@@ -152,7 +168,7 @@ def test_MPR2_matches_MPT2():
 def test_MPR4_matches_MPT4():
     mpr4 = MPRfile(os.path.join(testdata_dir, 'bio-logic4.mpr'))
     mpt4, comments = MPTfile(os.path.join(testdata_dir, 'bio-logic4.mpt'))
-    assert_MPR_matches_MPT(mpr4, mpt4)
+    assert_MPR_matches_MPT(mpr4, mpt4, comments)
 
 
 def test_MPR5_matches_MPT5():
@@ -160,11 +176,11 @@ def test_MPR5_matches_MPT5():
     mpt, comments = MPTfile((re.sub(b'\tXXX\t', b'\t0\t', line) for line in
                              open(os.path.join(testdata_dir, 'bio-logic5.mpt'),
                                   mode='rb')))
-    assert_MPR_matches_MPT(mpr, mpt)
+    assert_MPR_matches_MPT(mpr, mpt, comments)
 
 
 def test_MPR6_matches_MPT6():
     mpr = MPRfile(os.path.join(testdata_dir, 'bio-logic6.mpr'))
     mpt, comments = MPTfile(os.path.join(testdata_dir, 'bio-logic6.mpt'))
     mpr.data = mpr.data[:958]  # .mpt file is incomplete
-    assert_MPR_matches_MPT(mpr, mpt)
+    assert_MPR_matches_MPT(mpr, mpt, comments)