Day 2: parse time delta from log file

Author: kokesak

days/01-03-datetimes/code/day2/logtimes.py

@@ -0,0 +1,48 @@
+from datetime import datetime
+import os
+import urllib.request
+
+SHUTDOWN_EVENT = 'Shutdown initiated'
+
+# prep: read in the logfile
+tmp = os.getenv("TMP", "/tmp")
+logfile = os.path.join(tmp, 'log')
+urllib.request.urlretrieve(
+    'https://bites-data.s3.us-east-2.amazonaws.com/messages.log',
+    logfile
+)
+
+with open(logfile) as f:
+    loglines = f.readlines()
+
+# for you to code:
+
+def convert_to_datetime(line):
+    """TODO 1:
+       Extract timestamp from logline and convert it to a datetime object.
+       For example calling the function with:
+       INFO 2014-07-03T23:27:51 supybot Shutdown complete.
+       returns:
+       datetime(2014, 7, 3, 23, 27, 51)
+    """
+    date_string = line.split(' ')[1]
+    return datetime.strptime(date_string, '%Y-%m-%dT%H:%M:%S')
+
+
+def time_between_shutdowns(loglines):
+    """TODO 2:
+       Extract shutdown events ("Shutdown initiated") from loglines and
+       calculate the timedelta between the first and last one.
+       Return this datetime.timedelta object.
+    """
+    for line in loglines:
+        if SHUTDOWN_EVENT in line:
+            start = convert_to_datetime(line)
+            break
+
+    for line in reversed(loglines):
+        if SHUTDOWN_EVENT in line:
+            end = convert_to_datetime(line)
+            break
+
+    return end - start

days/01-03-datetimes/code/day2/test_logtimes.py

@@ -0,0 +1,18 @@
+from datetime import datetime, timedelta
+
+from logtimes import loglines, convert_to_datetime, time_between_shutdowns
+
+
+def test_convert_to_datetime():
+    line1 = 'ERROR 2014-07-03T23:24:31 supybot Invalid user dictionary file'
+    line2 = 'INFO 2015-10-03T10:12:51 supybot Shutdown initiated.'
+    line3 = 'INFO 2016-09-03T02:11:22 supybot Shutdown complete.'
+    assert convert_to_datetime(line1) == datetime(2014, 7, 3, 23, 24, 31)
+    assert convert_to_datetime(line2) == datetime(2015, 10, 3, 10, 12, 51)
+    assert convert_to_datetime(line3) == datetime(2016, 9, 3, 2, 11, 22)
+
+
+def test_time_between_events():
+    diff = time_between_shutdowns(loglines)
+    assert type(diff) == timedelta
+    assert str(diff) == '0:03:31'