make flake happy

17 files changed, 329 insertions, 262 deletions

diff --git a/src/isodate/__init__.py b/src/isodate/__init__.py
index 091af0a..26604c2 100644
--- a/src/isodate/__init__.py
+++ b/src/isodate/__init__.py
@@ -14,11 +14,11 @@
 #    may be used to endorse or promote products derived from this software
 #    without specific prior written permission.
 #
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
@@ -28,12 +28,12 @@
 Import all essential functions and constants to re-export them here for easy
 access.
 
-This module contains also various pre-defined ISO 8601 format strings. 
+This module contains also various pre-defined ISO 8601 format strings.
 '''
 from isodate.isodates import parse_date, date_isoformat
 from isodate.isotime import parse_time, time_isoformat
 from isodate.isodatetime import parse_datetime, datetime_isoformat
-from isodate.isoduration import parse_duration, duration_isoformat, Duration
+from isodate.isoduration import parse_duration, duration_isoformat
 from isodate.isoerror import ISO8601Error
 from isodate.isotzinfo import parse_tzinfo, tz_isoformat
 from isodate.tzinfo import UTC, FixedOffset, LOCAL
@@ -53,3 +53,18 @@ from isodate.isostrf import DT_BAS_ORD_COMPLETE, DT_EXT_ORD_COMPLETE
 from isodate.isostrf import DT_BAS_WEEK_COMPLETE, DT_EXT_WEEK_COMPLETE
 from isodate.isostrf import D_DEFAULT, D_WEEK, D_ALT_EXT, D_ALT_BAS
 from isodate.isostrf import D_ALT_BAS_ORD, D_ALT_EXT_ORD
+
+__all__ = (parse_date, date_isoformat, parse_time, time_isoformat,
+           parse_datetime, datetime_isoformat, parse_duration,
+           duration_isoformat, ISO8601Error, parse_tzinfo,
+           tz_isoformat, UTC, FixedOffset, LOCAL, Duration,
+           strftime, DATE_BAS_COMPLETE, DATE_BAS_ORD_COMPLETE,
+           DATE_BAS_WEEK, DATE_BAS_WEEK_COMPLETE, DATE_CENTURY,
+           DATE_EXT_COMPLETE, DATE_EXT_ORD_COMPLETE, DATE_EXT_WEEK,
+           DATE_EXT_WEEK_COMPLETE, DATE_MONTH, DATE_YEAR,
+           TIME_BAS_COMPLETE, TIME_BAS_MINUTE, TIME_EXT_COMPLETE,
+           TIME_EXT_MINUTE, TIME_HOUR, TZ_BAS, TZ_EXT, TZ_HOUR,
+           DT_BAS_COMPLETE, DT_EXT_COMPLETE, DT_BAS_ORD_COMPLETE,
+           DT_EXT_ORD_COMPLETE, DT_BAS_WEEK_COMPLETE,
+           DT_EXT_WEEK_COMPLETE, D_DEFAULT, D_WEEK, D_ALT_EXT,
+           D_ALT_BAS, D_ALT_BAS_ORD, D_ALT_EXT_ORD)
diff --git a/src/isodate/duration.py b/src/isodate/duration.py
index 4484919..62b14ca 100644
--- a/src/isodate/duration.py
+++ b/src/isodate/duration.py
@@ -40,8 +40,8 @@ def fquotmod(val, low, high):
 
     '''
     # assumes that all the maths is done with Decimals.
-    # divmod for Decimal uses truncate instead of floor as builtin divmod, so we have
-    # to do it manually here.
+    # divmod for Decimal uses truncate instead of floor as builtin
+    # divmod, so we have to do it manually here.
     a, b = val - low, high - low
     div = (a / b).to_integral(ROUND_FLOOR)
     mod = a - div * b
@@ -124,9 +124,9 @@ class Duration(object):
         Return a string suitable for repr(x) calls.
         '''
         return "%s.%s(%d, %d, %d, years=%d, months=%d)" % (
-                self.__class__.__module__, self.__class__.__name__,
-                self.tdelta.days, self.tdelta.seconds,
-                self.tdelta.microseconds, self.years, self.months)
+            self.__class__.__module__, self.__class__.__name__,
+            self.tdelta.days, self.tdelta.seconds,
+            self.tdelta.microseconds, self.years, self.months)
 
     def __neg__(self):
         """
@@ -153,8 +153,10 @@ class Duration(object):
             newduration.tdelta = self.tdelta + other.tdelta
             return newduration
         if isinstance(other, (date, datetime)):
-            if (not( float(self.years).is_integer() and float(self.months).is_integer())):
-                raise ValueError('fractional years or months not supported for date calculations')
+            if (not(float(self.years).is_integer()
+                    and float(self.months).is_integer())):
+                raise ValueError('fractional years or months not supported'
+                                 ' for date calculations')
             newmonth = other.month + self.months
             carry, newmonth = fquotmod(newmonth, 1, 13)
             newyear = other.year + self.years + carry
@@ -177,8 +179,10 @@ class Duration(object):
             newduration.tdelta = self.tdelta + other
             return newduration
         if isinstance(other, (date, datetime)):
-            if (not( float(self.years).is_integer() and float(self.months).is_integer())):
-                raise ValueError('fractional years or months not supported for date calculations')
+            if (not(float(self.years).is_integer()
+                    and float(self.months).is_integer())):
+                raise ValueError('fractional years or months not supported'
+                                 ' for date calculations')
             newmonth = other.month + self.months
             carry, newmonth = fquotmod(newmonth, 1, 13)
             newyear = other.year + self.years + carry
@@ -216,8 +220,10 @@ class Duration(object):
         '''
         #print '__rsub__:', self, other
         if isinstance(other, (date, datetime)):
-            if (not( float(self.years).is_integer() and float(self.months).is_integer())):
-                raise ValueError('fractional years or months not supported for date calculations')
+            if (not(float(self.years).is_integer()
+                    and float(self.months).is_integer())):
+                raise ValueError('fractional years or months not supported'
+                                 ' for date calculations')
             newmonth = other.month - self.months
             carry, newmonth = fquotmod(newmonth, 1, 13)
             newyear = other.year - self.years + carry
@@ -240,13 +246,14 @@ class Duration(object):
         If the years, month part and the timedelta part are both equal, then
         the two Durations are considered equal.
         '''
-        if (isinstance(other, timedelta) and
-            self.years == 0 and self.months == 0):
+        if ((isinstance(other, timedelta) and
+             self.years == 0 and self.months == 0)):
             return self.tdelta == other
         if not isinstance(other, Duration):
             return NotImplemented
-        if ((self.years * 12 + self.months) ==
-            (other.years * 12 + other.months) and self.tdelta == other.tdelta):
+        if (((self.years * 12 + self.months) ==
+             (other.years * 12 + other.months)
+             and self.tdelta == other.tdelta)):
             return True
         return False
 
@@ -255,12 +262,15 @@ class Duration(object):
         If the years, month part or the timedelta part is not equal, then
         the two Durations are considered not equal.
         '''
-        if isinstance(other, timedelta) and self.years == 0 and self.months == 0:
+        if ((isinstance(other, timedelta)
+             and self.years == 0
+             and self.months == 0)):
             return self.tdelta != other
         if not isinstance(other, Duration):
             return NotImplemented
-        if ((self.years * 12 + self.months) !=
-            (other.years * 12 + other.months) or self.tdelta != other.tdelta):
+        if (((self.years * 12 + self.months) !=
+             (other.years * 12 + other.months)
+             or self.tdelta != other.tdelta)):
             return True
         return False
 
diff --git a/src/isodate/isodates.py b/src/isodate/isodates.py
index 8bafa20..aee7417 100644
--- a/src/isodate/isodates.py
+++ b/src/isodate/isodates.py
@@ -14,11 +14,11 @@
 #    may be used to endorse or promote products derived from this software
 #    without specific prior written permission.
 #
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
@@ -42,18 +42,19 @@ DATE_REGEX_CACHE = {}
 # A dictionary to cache pre-compiled regular expressions.
 # A set of regular expressions is identified, by number of year digits allowed
 # and whether a plus/minus sign is required or not. (This option is changeable
-# only for 4 digit years).  
+# only for 4 digit years).
+
 
 def build_date_regexps(yeardigits=4, expanded=False):
     '''
     Compile set of regular expressions to parse ISO dates. The expressions will
     be created only if they are not already in REGEX_CACHE.
-    
+
     It is necessary to fix the number of year digits, else it is not possible
     to automatically distinguish between various ISO date formats.
-    
+
     ISO 8601 allows more than 4 digit years, on prior agreement, but then a +/-
-    sign is required (expanded format). To support +/- sign for 4 digit years, 
+    sign is required (expanded format). To support +/- sign for 4 digit years,
     the expanded parameter needs to be set to True.
     '''
     if yeardigits != 4:
@@ -73,7 +74,7 @@ def build_date_regexps(yeardigits=4, expanded=False):
                                       % (sign, yeardigits)))
         #    YYYYMMDD or +- YYYYYYMMDD... basic date format
         cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})"
-                                      r"(?P<month>[0-9]{2})(?P<day>[0-9]{2})" 
+                                      r"(?P<month>[0-9]{2})(?P<day>[0-9]{2})"
                                       % (sign, yeardigits)))
         # 2. complete week dates:
         #    YYYY-Www-D or +-YYYYYY-Www-D ... extended week date
@@ -98,7 +99,7 @@ def build_date_regexps(yeardigits=4, expanded=False):
         cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})"
                                       r"-W(?P<week>[0-9]{2})"
                                       % (sign, yeardigits)))
-        #    YYYYWww or +-YYYYYYWww ... basic reduced accuracy week date 
+        #    YYYYWww or +-YYYYYYWww ... basic reduced accuracy week date
         cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})W"
                                       r"(?P<week>[0-9]{2})"
                                       % (sign, yeardigits)))
@@ -120,18 +121,19 @@ def build_date_regexps(yeardigits=4, expanded=False):
         DATE_REGEX_CACHE[(yeardigits, expanded)] = cache_entry
     return DATE_REGEX_CACHE[(yeardigits, expanded)]
 
+
 def parse_date(datestring, yeardigits=4, expanded=False):
     '''
     Parse an ISO 8601 date string into a datetime.date object.
-    
+
     As the datetime.date implementation is limited to dates starting from
     0001-01-01, negative dates (BC) and year 0 can not be parsed by this
     method.
-    
+
     For incomplete dates, this method chooses the first day for it. For
-    instance if only a century is given, this method returns the 1st of 
+    instance if only a century is given, this method returns the 1st of
     January in year 1 of this century.
-    
+
     supported formats: (expanded formats are shown with 6 digits for year)
       YYYYMMDD    +-YYYYYYMMDD      basic complete date
       YYYY-MM-DD  +-YYYYYY-MM-DD    extended complete date
@@ -149,10 +151,10 @@ def parse_date(datestring, yeardigits=4, expanded=False):
     @param yeardigits: how many digits are used to represent a year
     @param expanded: if True then +/- signs are allowed. This parameter
                      is forced to True, if yeardigits != 4
-                     
+
     @return: a datetime.date instance represented by datestring
     @raise ISO8601Error: if this function can not parse the datestring
-    @raise ValueError: if datestring can not be represented by datetime.date 
+    @raise ValueError: if datestring can not be represented by datetime.date
     '''
     if yeardigits != 4:
         expanded = True
@@ -163,10 +165,10 @@ def parse_date(datestring, yeardigits=4, expanded=False):
             groups = match.groupdict()
             # sign, century, year, month, week, day,
             # FIXME: negative dates not possible with python standard types
-            sign = (groups['sign'] == '-' and -1) or 1 
+            sign = (groups['sign'] == '-' and -1) or 1
             if 'century' in groups:
                 return date(sign * (int(groups['century']) * 100 + 1), 1, 1)
-            if not 'month' in groups: # weekdate or ordinal date
+            if not 'month' in groups:  # weekdate or ordinal date
                 ret = date(sign * int(groups['year']), 1, 1)
                 if 'week' in groups:
                     isotuple = ret.isocalendar()
@@ -175,10 +177,10 @@ def parse_date(datestring, yeardigits=4, expanded=False):
                     else:
                         days = 1
                     # if first week in year, do weeks-1
-                    return ret + timedelta(weeks=int(groups['week']) - 
-                                            (((isotuple[1] == 1) and 1) or 0),
-                                           days = -isotuple[2] + days)
-                elif 'day' in groups: # ordinal date
+                    return ret + timedelta(weeks=int(groups['week']) -
+                                           (((isotuple[1] == 1) and 1) or 0),
+                                           days=-isotuple[2] + days)
+                elif 'day' in groups:  # ordinal date
                     return ret + timedelta(days=int(groups['day'])-1)
                 else:  # year date
                     return ret
@@ -187,14 +189,15 @@ def parse_date(datestring, yeardigits=4, expanded=False):
                 day = 1
             else:
                 day = int(groups['day'])
-            return date(sign * int(groups['year']), 
+            return date(sign * int(groups['year']),
                         int(groups['month']) or 1, day)
     raise ISO8601Error('Unrecognised ISO 8601 date format: %r' % datestring)
 
+
 def date_isoformat(tdate, format=DATE_EXT_COMPLETE, yeardigits=4):
     '''
-    Format date strings. 
-    
+    Format date strings.
+
     This method is just a wrapper around isodate.isostrf.strftime and uses
     Date-Extended-Complete as default format.
     '''
diff --git a/src/isodate/isodatetime.py b/src/isodate/isodatetime.py
index 7e4d570..147474b 100644
--- a/src/isodate/isodatetime.py
+++ b/src/isodate/isodatetime.py
@@ -14,11 +14,11 @@
 #    may be used to endorse or promote products derived from this software
 #    without specific prior written permission.
 #
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
@@ -37,10 +37,11 @@ from isodate.isostrf import DATE_EXT_COMPLETE, TIME_EXT_COMPLETE, TZ_EXT
 from isodate.isodates import parse_date
 from isodate.isotime import parse_time
 
+
 def parse_datetime(datetimestring):
     '''
     Parses ISO 8601 date-times into datetime.datetime objects.
-    
+
     This function uses parse_date and parse_time to do the job, so it allows
     more combinations of date and time representations, than the actual
     ISO 8601:2004 standard allows.
@@ -50,11 +51,12 @@ def parse_datetime(datetimestring):
     tmptime = parse_time(timestring)
     return datetime.combine(tmpdate, tmptime)
 
-def datetime_isoformat(tdt, format=DATE_EXT_COMPLETE + 'T' + 
-                                   TIME_EXT_COMPLETE + TZ_EXT):
+
+def datetime_isoformat(tdt, format=DATE_EXT_COMPLETE + 'T' +
+                       TIME_EXT_COMPLETE + TZ_EXT):
     '''
-    Format datetime strings. 
-    
+    Format datetime strings.
+
     This method is just a wrapper around isodate.isostrf.strftime and uses
     Extended-Complete as default format.
     '''
diff --git a/src/isodate/isoduration.py b/src/isodate/isoduration.py
index 97affdc..a229186 100644
--- a/src/isodate/isoduration.py
+++ b/src/isodate/isoduration.py
@@ -39,14 +39,15 @@ from isodate.isoerror import ISO8601Error
 from isodate.isodatetime import parse_datetime
 from isodate.isostrf import strftime, D_DEFAULT
 
-ISO8601_PERIOD_REGEX = re.compile(r"^(?P<sign>[+-])?"
-                r"P(?P<years>[0-9]+([,.][0-9]+)?Y)?"
-                r"(?P<months>[0-9]+([,.][0-9]+)?M)?"
-                r"(?P<weeks>[0-9]+([,.][0-9]+)?W)?"
-                r"(?P<days>[0-9]+([,.][0-9]+)?D)?"
-                r"((?P<separator>T)(?P<hours>[0-9]+([,.][0-9]+)?H)?"
-                r"(?P<minutes>[0-9]+([,.][0-9]+)?M)?"
-                r"(?P<seconds>[0-9]+([,.][0-9]+)?S)?)?$")
+ISO8601_PERIOD_REGEX = re.compile(
+    r"^(?P<sign>[+-])?"
+    r"P(?P<years>[0-9]+([,.][0-9]+)?Y)?"
+    r"(?P<months>[0-9]+([,.][0-9]+)?M)?"
+    r"(?P<weeks>[0-9]+([,.][0-9]+)?W)?"
+    r"(?P<days>[0-9]+([,.][0-9]+)?D)?"
+    r"((?P<separator>T)(?P<hours>[0-9]+([,.][0-9]+)?H)?"
+    r"(?P<minutes>[0-9]+([,.][0-9]+)?M)?"
+    r"(?P<seconds>[0-9]+([,.][0-9]+)?S)?)?$")
 # regular expression to parse ISO duartion strings.
 
 
@@ -107,7 +108,8 @@ def parse_duration(datestring):
             if key in ('years', 'months'):
                 groups[key] = Decimal(groups[key][:-1].replace(',', '.'))
             else:
-                # these values are passed into a timedelta object, which works with floats.
+                # these values are passed into a timedelta object,
+                # which works with floats.
                 groups[key] = float(groups[key][:-1].replace(',', '.'))
     if groups["years"] == 0 and groups["months"] == 0:
         ret = timedelta(days=groups["days"], hours=groups["hours"],
@@ -134,10 +136,11 @@ def duration_isoformat(tduration, format=D_DEFAULT):
     '''
     # TODO: implement better decision for negative Durations.
     #       should be done in Duration class in consistent way with timedelta.
-    if ((isinstance(tduration, Duration) and (tduration.years < 0 or
-                                             tduration.months < 0 or
-                                             tduration.tdelta < timedelta(0)))
-        or (isinstance(tduration, timedelta) and (tduration < timedelta(0)))):
+    if (((isinstance(tduration, Duration)
+          and (tduration.years < 0 or tduration.months < 0
+               or tduration.tdelta < timedelta(0)))
+         or (isinstance(tduration, timedelta)
+             and (tduration < timedelta(0))))):
         ret = '-'
     else:
         ret = ''
diff --git a/src/isodate/isoerror.py b/src/isodate/isoerror.py
index edbc5aa..e7b211b 100644
--- a/src/isodate/isoerror.py
+++ b/src/isodate/isoerror.py
@@ -14,11 +14,11 @@
 #    may be used to endorse or promote products derived from this software
 #    without specific prior written permission.
 #
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
@@ -28,5 +28,6 @@
 This module defines all exception classes in the whole package.
 '''
 
+
 class ISO8601Error(ValueError):
     '''Raised when the given ISO string can not be parsed.'''
diff --git a/src/isodate/isostrf.py b/src/isodate/isostrf.py
index 5f3169f..1afc810 100644
--- a/src/isodate/isostrf.py
+++ b/src/isodate/isostrf.py
@@ -69,10 +69,10 @@ DT_EXT_COMPLETE = DATE_EXT_COMPLETE + 'T' + TIME_EXT_COMPLETE + TZ_EXT
 DT_BAS_COMPLETE = DATE_BAS_COMPLETE + 'T' + TIME_BAS_COMPLETE + TZ_BAS
 DT_EXT_ORD_COMPLETE = DATE_EXT_ORD_COMPLETE + 'T' + TIME_EXT_COMPLETE + TZ_EXT
 DT_BAS_ORD_COMPLETE = DATE_BAS_ORD_COMPLETE + 'T' + TIME_BAS_COMPLETE + TZ_BAS
-DT_EXT_WEEK_COMPLETE = DATE_EXT_WEEK_COMPLETE + 'T' + TIME_EXT_COMPLETE +\
-                       TZ_EXT
-DT_BAS_WEEK_COMPLETE = DATE_BAS_WEEK_COMPLETE + 'T' + TIME_BAS_COMPLETE +\
-                       TZ_BAS
+DT_EXT_WEEK_COMPLETE = (DATE_EXT_WEEK_COMPLETE + 'T' +
+                        TIME_EXT_COMPLETE + TZ_EXT)
+DT_BAS_WEEK_COMPLETE = (DATE_BAS_WEEK_COMPLETE + 'T' +
+                        TIME_BAS_COMPLETE + TZ_BAS)
 
 # Duration formts
 D_DEFAULT = 'P%P'
@@ -86,17 +86,19 @@ STRF_DT_MAP = {'%d': lambda tdt, yds: '%02d' % tdt.day,
                '%f': lambda tdt, yds: '%06d' % tdt.microsecond,
                '%H': lambda tdt, yds: '%02d' % tdt.hour,
                '%j': lambda tdt, yds: '%03d' % (tdt.toordinal() -
-                                            date(tdt.year, 1, 1).toordinal() +
-                                            1),
+                                                date(tdt.year,
+                                                     1, 1).toordinal() +
+                                                1),
                '%m': lambda tdt, yds: '%02d' % tdt.month,
                '%M': lambda tdt, yds: '%02d' % tdt.minute,
                '%S': lambda tdt, yds: '%02d' % tdt.second,
                '%w': lambda tdt, yds: '%1d' % tdt.isoweekday(),
                '%W': lambda tdt, yds: '%02d' % tdt.isocalendar()[1],
-               '%Y': lambda tdt, yds: (((yds != 4) and '+') or '') +\
-                                   (('%%0%dd' % yds) % tdt.year),
-               '%C': lambda tdt, yds: (((yds != 4) and '+') or '') +\
-                                   (('%%0%dd' % (yds - 2)) % (tdt.year / 100)),
+               '%Y': lambda tdt, yds: (((yds != 4) and '+') or '') +
+                                      (('%%0%dd' % yds) % tdt.year),
+               '%C': lambda tdt, yds: (((yds != 4) and '+') or '') +
+                                      (('%%0%dd' % (yds - 2)) %
+                                       (tdt.year / 100)),
                '%h': lambda tdt, yds: tz_isoformat(tdt, '%h'),
                '%Z': lambda tdt, yds: tz_isoformat(tdt, '%Z'),
                '%z': lambda tdt, yds: tz_isoformat(tdt, '%z'),
@@ -109,11 +111,11 @@ STRF_D_MAP = {'%d': lambda tdt, yds: '%02d' % tdt.days,
               '%M': lambda tdt, yds: '%02d' % ((tdt.seconds / 60) % 60),
               '%S': lambda tdt, yds: '%02d' % (tdt.seconds % 60),
               '%W': lambda tdt, yds: '%02d' % (abs(tdt.days / 7)),
-              '%Y': lambda tdt, yds: (((yds != 4) and '+') or '') +\
-                                   (('%%0%dd' % yds) % tdt.years),
-              '%C': lambda tdt, yds: (((yds != 4) and '+') or '') +\
-                                   (('%%0%dd' % (yds - 2)) %
-                                    (tdt.years / 100)),
+              '%Y': lambda tdt, yds: (((yds != 4) and '+') or '') +
+                                     (('%%0%dd' % yds) % tdt.years),
+              '%C': lambda tdt, yds: (((yds != 4) and '+') or '') +
+                                     (('%%0%dd' % (yds - 2)) %
+                                      (tdt.years / 100)),
               '%%': lambda tdt, yds: '%'}
 
 
@@ -183,24 +185,28 @@ def _strfdt(tdt, format, yeardigits=4):
 
 
 def strftime(tdt, format, yeardigits=4):
-    '''
-    Directive    Meaning    Notes
+    '''Directive    Meaning    Notes
     %d    Day of the month as a decimal number [01,31].
-    %f    Microsecond as a decimal number [0,999999], zero-padded on the left (1)
+    %f    Microsecond as a decimal number [0,999999], zero-padded
+          on the left (1)
     %H    Hour (24-hour clock) as a decimal number [00,23].
     %j    Day of the year as a decimal number [001,366].
     %m    Month as a decimal number [01,12].
     %M    Minute as a decimal number [00,59].
     %S    Second as a decimal number [00,61].    (3)
     %w    Weekday as a decimal number [0(Monday),6].
-    %W    Week number of the year (Monday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Monday are considered to be in week 0.    (4)
+    %W    Week number of the year (Monday as the first day of the week)
+          as a decimal number [00,53]. All days in a new year preceding the
+          first Monday are considered to be in week 0.  (4)
     %Y    Year with century as a decimal number. [0000,9999]
     %C    Century as a decimal number. [00,99]
-    %z    UTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).    (5)
+    %z    UTC offset in the form +HHMM or -HHMM (empty string if the
+          object is naive).    (5)
     %Z    Time zone name (empty string if the object is naive).
     %P    ISO8601 duration format.
     %p    ISO8601 duration format in weeks.
     %%    A literal '%' character.
+
     '''
     if isinstance(tdt, (timedelta, Duration)):
         return _strfduration(tdt, format, yeardigits)
diff --git a/src/isodate/isotime.py b/src/isodate/isotime.py
index 7ded2d4..2b268d0 100644
--- a/src/isodate/isotime.py
+++ b/src/isodate/isotime.py
@@ -129,7 +129,8 @@ def parse_time(timestring):
                 # int(...) ... no rounding
                 # to_integral() ... rounding
                 return time(int(groups['hour']), int(groups['minute']),
-                            int(second), int(microsecond.to_integral()), tzinfo)
+                            int(second), int(microsecond.to_integral()),
+                            tzinfo)
             if 'minute' in groups:
                 minute = Decimal(groups['minute'])
                 second = (minute - int(minute)) * 60
diff --git a/src/isodate/isotzinfo.py b/src/isodate/isotzinfo.py
index 97dbe8c..263afd7 100644
--- a/src/isodate/isotzinfo.py
+++ b/src/isodate/isotzinfo.py
@@ -14,11 +14,11 @@
 #    may be used to endorse or promote products derived from this software
 #    without specific prior written permission.
 #
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
@@ -27,7 +27,7 @@
 '''
 This module provides an ISO 8601:2004 time zone info parser.
 
-It offers a function to parse the time zone offset as specified by ISO 8601. 
+It offers a function to parse the time zone offset as specified by ISO 8601.
 '''
 import re
 
@@ -39,10 +39,11 @@ TZ_REGEX = r"(?P<tzname>(Z|(?P<tzsign>[+-])"\
 
 TZ_RE = re.compile(TZ_REGEX)
 
+
 def build_tzinfo(tzname, tzsign='+', tzhour=0, tzmin=0):
     '''
     create a tzinfo instance according to given parameters.
-    
+
     tzname:
       'Z'       ... return UTC
       '' | None ... return None
@@ -55,10 +56,11 @@ def build_tzinfo(tzname, tzsign='+', tzhour=0, tzmin=0):
     tzsign = ((tzsign == '-') and -1) or 1
     return FixedOffset(tzsign * tzhour, tzsign * tzmin, tzname)
 
+
 def parse_tzinfo(tzstring):
     '''
     Parses ISO 8601 time zone designators to tzinfo objecs.
-    
+
     A time zone designator can be in the following format:
               no designator indicates local time zone
       Z       UTC
@@ -69,19 +71,20 @@ def parse_tzinfo(tzstring):
     match = TZ_RE.match(tzstring)
     if match:
         groups = match.groupdict()
-        return build_tzinfo(groups['tzname'], groups['tzsign'], 
-                            int(groups['tzhour'] or 0), 
+        return build_tzinfo(groups['tzname'], groups['tzsign'],
+                            int(groups['tzhour'] or 0),
                             int(groups['tzmin'] or 0))
     raise ISO8601Error('%s not a valid time zone info' % tzstring)
 
+
 def tz_isoformat(dt, format='%Z'):
     '''
-    return time zone offset ISO 8601 formatted. 
+    return time zone offset ISO 8601 formatted.
     The various ISO formats can be chosen with the format parameter.
-    
+
     if tzinfo is None returns ''
     if tzinfo is UTC returns 'Z'
-    else the offset is rendered to the given format. 
+    else the offset is rendered to the given format.
     format:
         %h ... +-HH
         %z ... +-HHMM
diff --git a/src/isodate/tests/__init__.py b/src/isodate/tests/__init__.py
index bc1867d..09dba2e 100644
--- a/src/isodate/tests/__init__.py
+++ b/src/isodate/tests/__init__.py
@@ -32,6 +32,7 @@ import unittest
 from isodate.tests import (test_date, test_time, test_datetime, test_duration,
                            test_strf, test_pickle)
 
+
 def test_suite():
     '''
     Return a new TestSuite instance consisting of all available TestSuites.
diff --git a/src/isodate/tests/test_date.py b/src/isodate/tests/test_date.py
index 3a1b4a6..fdc1043 100644
--- a/src/isodate/tests/test_date.py
+++ b/src/isodate/tests/test_date.py
@@ -14,11 +14,11 @@
 #    may be used to endorse or promote products derived from this software
 #    without specific prior written permission.
 #
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
@@ -66,20 +66,21 @@ TEST_CASES = {4: [('19', date(1901, 1, 1), DATE_CENTURY),
                   ('+001985W15', date(1985, 4, 8), DATE_BAS_WEEK),
                   ('+001985-W15', date(1985, 4, 8), DATE_EXT_WEEK)]}
 
+
 def create_testcase(yeardigits, datestring, expectation, format):
     '''
     Create a TestCase class for a specific test.
-    
+
     This allows having a separate TestCase for each test tuple from the
     TEST_CASES list, so that a failed test won't stop other tests.
     '''
-    
+
     class TestDate(unittest.TestCase):
         '''
         A test case template to parse an ISO date string into a date
         object.
         '''
-        
+
         def test_parse(self):
             '''
             Parse an ISO date string and compare it to the expected value.
@@ -90,7 +91,7 @@ def create_testcase(yeardigits, datestring, expectation, format):
             else:
                 result = parse_date(datestring, yeardigits)
                 self.assertEqual(result, expectation)
-                
+
         def test_format(self):
             '''
             Take date object and create ISO string from it.
@@ -98,15 +99,16 @@ def create_testcase(yeardigits, datestring, expectation, format):
             '''
             if expectation is None:
                 self.assertRaises(AttributeError,
-                                  date_isoformat, expectation, format, 
-                                                  yeardigits)
+                                  date_isoformat, expectation, format,
+                                  yeardigits)
             else:
                 self.assertEqual(date_isoformat(expectation, format,
                                                 yeardigits),
                                  datestring)
-            
+
     return unittest.TestLoader().loadTestsFromTestCase(TestDate)
 
+
 def test_suite():
     '''
     Construct a TestSuite instance for all test cases.
@@ -118,9 +120,10 @@ def test_suite():
                                           expectation, format))
     return suite
 
+
 # load_tests Protocol
 def load_tests(loader, tests, pattern):
     return test_suite()
-    
+
 if __name__ == '__main__':
     unittest.main(defaultTest='test_suite')
diff --git a/src/isodate/tests/test_datetime.py b/src/isodate/tests/test_datetime.py
index f6aaa51..73b1982 100644
--- a/src/isodate/tests/test_datetime.py
+++ b/src/isodate/tests/test_datetime.py
@@ -82,7 +82,7 @@ TEST_CASES = [('19850412T1015', datetime(1985, 4, 12, 10, 15),
                datetime(2012, 10, 30, 8, 55, 22, 123456, tzinfo=UTC),
                DATE_EXT_COMPLETE + 'T' + TIME_EXT_COMPLETE + '.%f' + TZ_BAS,
                '2012-10-30T08:55:22.123456Z')
-               ]
+              ]
 
 
 def create_testcase(datetimestring, expectation, format, output):
@@ -127,12 +127,14 @@ def test_suite():
     '''
     suite = unittest.TestSuite()
     for datetimestring, expectation, format, output in TEST_CASES:
-        suite.addTest(create_testcase(datetimestring, expectation, format, output))
+        suite.addTest(create_testcase(datetimestring, expectation,
+                                      format, output))
     return suite
 
+
 # load_tests Protocol
 def load_tests(loader, tests, pattern):
     return test_suite()
-    
+
 if __name__ == '__main__':
     unittest.main(defaultTest='test_suite')
diff --git a/src/isodate/tests/test_duration.py b/src/isodate/tests/test_duration.py
index e69ae17..c664120 100644
--- a/src/isodate/tests/test_duration.py
+++ b/src/isodate/tests/test_duration.py
@@ -55,7 +55,7 @@ PARSE_TEST_CASES = {'P18Y9M4DT11H9M8S': (Duration(4, 8, 0, 0, 9, 11, 0, 9, 18),
                     '-P2.2W': (timedelta(weeks=-2.2), D_DEFAULT,
                                '-P15DT9H36M'),
                     'P1DT2H3M4S': (timedelta(days=1, hours=2, minutes=3,
-                                            seconds=4), D_DEFAULT, None),
+                                             seconds=4), D_DEFAULT, None),
                     'P1DT2H3M': (timedelta(days=1, hours=2, minutes=3),
                                  D_DEFAULT, None),
                     'P1DT2H': (timedelta(days=1, hours=2), D_DEFAULT, None),
@@ -98,137 +98,138 @@ MATH_TEST_CASES = (('P5Y7M1DT9H45M16.72S', 'PT27M24.68S',
                    ('PT1H1.95S', 'P1332DT55M0.33S',
                     'P1332DT1H55M2.28S', '-P1331DT23H54M58.38S', False))
 
+
 # A list of test cases to test addition and subtraction of date/datetime
 # and Duration objects. They are tested against the results of an
 # equal long timedelta duration.
-DATE_TEST_CASES = ( (date(2008, 2, 29),
-                     timedelta(days=10, hours=12, minutes=20),
-                     Duration(days=10, hours=12, minutes=20)),
-                    (date(2008, 1, 31),
-                     timedelta(days=10, hours=12, minutes=20),
-                     Duration(days=10, hours=12, minutes=20)),
-                    (datetime(2008, 2, 29),
-                     timedelta(days=10, hours=12, minutes=20),
-                     Duration(days=10, hours=12, minutes=20)),
-                    (datetime(2008, 1, 31),
-                     timedelta(days=10, hours=12, minutes=20),
-                     Duration(days=10, hours=12, minutes=20)),
-                    (datetime(2008, 4, 21),
-                     timedelta(days=10, hours=12, minutes=20),
-                     Duration(days=10, hours=12, minutes=20)),
-                    (datetime(2008, 5, 5),
-                     timedelta(days=10, hours=12, minutes=20),
-                     Duration(days=10, hours=12, minutes=20)),
-                    (datetime(2000, 1, 1),
-                     timedelta(hours=-33),
-                     Duration(hours=-33)),
-                    (datetime(2008, 5, 5),
-                     Duration(years=1, months=1, days=10, hours=12,
-                              minutes=20),
-                     Duration(months=13, days=10, hours=12, minutes=20)),
-                    (datetime(2000, 3, 30),
-                     Duration(years=1, months=1, days=10, hours=12,
-                              minutes=20),
-                     Duration(months=13, days=10, hours=12, minutes=20)),
-                     )
+DATE_TEST_CASES = ((date(2008, 2, 29),
+                    timedelta(days=10, hours=12, minutes=20),
+                    Duration(days=10, hours=12, minutes=20)),
+                   (date(2008, 1, 31),
+                    timedelta(days=10, hours=12, minutes=20),
+                    Duration(days=10, hours=12, minutes=20)),
+                   (datetime(2008, 2, 29),
+                    timedelta(days=10, hours=12, minutes=20),
+                    Duration(days=10, hours=12, minutes=20)),
+                   (datetime(2008, 1, 31),
+                    timedelta(days=10, hours=12, minutes=20),
+                    Duration(days=10, hours=12, minutes=20)),
+                   (datetime(2008, 4, 21),
+                    timedelta(days=10, hours=12, minutes=20),
+                    Duration(days=10, hours=12, minutes=20)),
+                   (datetime(2008, 5, 5),
+                    timedelta(days=10, hours=12, minutes=20),
+                    Duration(days=10, hours=12, minutes=20)),
+                   (datetime(2000, 1, 1),
+                    timedelta(hours=-33),
+                    Duration(hours=-33)),
+                   (datetime(2008, 5, 5),
+                    Duration(years=1, months=1, days=10, hours=12,
+                             minutes=20),
+                    Duration(months=13, days=10, hours=12, minutes=20)),
+                   (datetime(2000, 3, 30),
+                    Duration(years=1, months=1, days=10, hours=12,
+                             minutes=20),
+                    Duration(months=13, days=10, hours=12, minutes=20)),
+                   )
 
 # A list of test cases of additon of date/datetime and Duration. The results
 # are compared against a given expected result.
 DATE_CALC_TEST_CASES = (
-                    (date(2000, 2, 1),
-                     Duration(years=1, months=1),
-                     date(2001, 3, 1)),
-                    (date(2000, 2, 29),
-                     Duration(years=1, months=1),
-                     date(2001, 3, 29)),
-                    (date(2000, 2, 29),
-                     Duration(years=1),
-                     date(2001, 2, 28)),
-                    (date(1996, 2, 29),
-                     Duration(years=4),
-                     date(2000, 2, 29)),
-                    (date(2096, 2, 29),
-                     Duration(years=4),
-                     date(2100, 2, 28)),
-                    (date(2000, 2, 1),
-                     Duration(years=-1, months=-1),
-                     date(1999, 1, 1)),
-                    (date(2000, 2, 29),
-                     Duration(years=-1, months=-1),
-                     date(1999, 1, 29)),
-                    (date(2000, 2, 1),
-                     Duration(years=1, months=1, days=1),
-                     date(2001, 3, 2)),
-                    (date(2000, 2, 29),
-                     Duration(years=1, months=1, days=1),
-                     date(2001, 3, 30)),
-                    (date(2000, 2, 29),
-                     Duration(years=1, days=1),
-                     date(2001, 3, 1)),
-                    (date(1996, 2, 29),
-                     Duration(years=4, days=1),
-                     date(2000, 3, 1)),
-                    (date(2096, 2, 29),
-                     Duration(years=4, days=1),
-                     date(2100, 3, 1)),
-                    (date(2000, 2, 1),
-                     Duration(years=-1, months=-1, days=-1),
-                     date(1998, 12, 31)),
-                    (date(2000, 2, 29),
-                     Duration(years=-1, months=-1, days=-1),
-                     date(1999, 1, 28)),
-                    (date(2001, 4, 1),
-                     Duration(years=-1, months=-1, days=-1),
-                     date(2000, 2, 29)),
-                    (date(2000, 4, 1),
-                     Duration(years=-1, months=-1, days=-1),
-                     date(1999, 2, 28)),
-                    (Duration(years=1, months=2),
-                     Duration(years=0, months=0, days=1),
-                     Duration(years=1, months=2, days=1)),
-                    (Duration(years=-1, months=-1, days=-1),
-                     date(2000, 4, 1),
-                     date(1999, 2, 28)),
-                    (Duration(years=1, months=1, weeks=5),
-                     date(2000, 1, 30),
-                     date(2001, 4, 4)),
-                    (parse_duration("P1Y1M5W"),
-                     date(2000, 1, 30),
-                     date(2001, 4, 4)),
-                    (parse_duration("P0.5Y"),
-                     date(2000, 1, 30),
-                     None),
-                    (Duration(years=1, months=1, hours=3),
-                     datetime(2000, 1, 30, 12, 15, 00),
-                     datetime(2001, 2, 28, 15, 15, 00)),
-                    (parse_duration("P1Y1MT3H"),
-                     datetime(2000, 1, 30, 12, 15, 00),
-                     datetime(2001, 2, 28, 15, 15, 00)),
-                    (Duration(years=1, months=2),
-                     timedelta(days=1),
-                     Duration(years=1, months=2, days=1)),
-                    (timedelta(days=1),
-                     Duration(years=1, months=2),
-                     Duration(years=1, months=2, days=1)),
-                    (datetime(2008, 1, 1, 0, 2),
-                     Duration(months=1),
-                     datetime(2008, 2, 1, 0, 2)),
-                    (datetime.strptime("200802", "%Y%M"),
-                     parse_duration("P1M"),
-                     datetime(2008, 2, 1, 0, 2)),
-                    (datetime(2008, 2, 1),
-                     Duration(months=1),
-                     datetime(2008, 3, 1)),
-                    (datetime.strptime("200802", "%Y%m"),
-                     parse_duration("P1M"),
-                     datetime(2008, 3, 1)),
-                    # (date(2000, 1, 1),
-                    #  Duration(years=1.5),
-                    #  date(2001, 6, 1)),
-                    # (date(2000, 1, 1),
-                    #  Duration(years=1, months=1.5),
-                    #  date(2001, 2, 14)),
-                    )
+    (date(2000, 2, 1),
+     Duration(years=1, months=1),
+     date(2001, 3, 1)),
+    (date(2000, 2, 29),
+     Duration(years=1, months=1),
+     date(2001, 3, 29)),
+    (date(2000, 2, 29),
+     Duration(years=1),
+     date(2001, 2, 28)),
+    (date(1996, 2, 29),
+     Duration(years=4),
+     date(2000, 2, 29)),
+    (date(2096, 2, 29),
+     Duration(years=4),
+     date(2100, 2, 28)),
+    (date(2000, 2, 1),
+     Duration(years=-1, months=-1),
+     date(1999, 1, 1)),
+    (date(2000, 2, 29),
+     Duration(years=-1, months=-1),
+     date(1999, 1, 29)),
+    (date(2000, 2, 1),
+     Duration(years=1, months=1, days=1),
+     date(2001, 3, 2)),
+    (date(2000, 2, 29),
+     Duration(years=1, months=1, days=1),
+     date(2001, 3, 30)),
+    (date(2000, 2, 29),
+     Duration(years=1, days=1),
+     date(2001, 3, 1)),
+    (date(1996, 2, 29),
+     Duration(years=4, days=1),
+     date(2000, 3, 1)),
+    (date(2096, 2, 29),
+     Duration(years=4, days=1),
+     date(2100, 3, 1)),
+    (date(2000, 2, 1),
+     Duration(years=-1, months=-1, days=-1),
+     date(1998, 12, 31)),
+    (date(2000, 2, 29),
+     Duration(years=-1, months=-1, days=-1),
+     date(1999, 1, 28)),
+    (date(2001, 4, 1),
+     Duration(years=-1, months=-1, days=-1),
+     date(2000, 2, 29)),
+    (date(2000, 4, 1),
+     Duration(years=-1, months=-1, days=-1),
+     date(1999, 2, 28)),
+    (Duration(years=1, months=2),
+     Duration(years=0, months=0, days=1),
+     Duration(years=1, months=2, days=1)),
+    (Duration(years=-1, months=-1, days=-1),
+     date(2000, 4, 1),
+     date(1999, 2, 28)),
+    (Duration(years=1, months=1, weeks=5),
+     date(2000, 1, 30),
+     date(2001, 4, 4)),
+    (parse_duration("P1Y1M5W"),
+     date(2000, 1, 30),
+     date(2001, 4, 4)),
+    (parse_duration("P0.5Y"),
+     date(2000, 1, 30),
+     None),
+    (Duration(years=1, months=1, hours=3),
+     datetime(2000, 1, 30, 12, 15, 00),
+     datetime(2001, 2, 28, 15, 15, 00)),
+    (parse_duration("P1Y1MT3H"),
+     datetime(2000, 1, 30, 12, 15, 00),
+     datetime(2001, 2, 28, 15, 15, 00)),
+    (Duration(years=1, months=2),
+     timedelta(days=1),
+     Duration(years=1, months=2, days=1)),
+    (timedelta(days=1),
+     Duration(years=1, months=2),
+     Duration(years=1, months=2, days=1)),
+    (datetime(2008, 1, 1, 0, 2),
+     Duration(months=1),
+     datetime(2008, 2, 1, 0, 2)),
+    (datetime.strptime("200802", "%Y%M"),
+     parse_duration("P1M"),
+     datetime(2008, 2, 1, 0, 2)),
+    (datetime(2008, 2, 1),
+     Duration(months=1),
+     datetime(2008, 3, 1)),
+    (datetime.strptime("200802", "%Y%m"),
+     parse_duration("P1M"),
+     datetime(2008, 3, 1)),
+    # (date(2000, 1, 1),
+    #  Duration(years=1.5),
+    #  date(2001, 6, 1)),
+    # (date(2000, 1, 1),
+    #  Duration(years=1, months=1.5),
+    #  date(2001, 2, 14)),
+    )
 
 
 class DurationTest(unittest.TestCase):
@@ -340,11 +341,14 @@ class DurationTest(unittest.TestCase):
         Test conversion form Duration to timedelta.
         '''
         dur = Duration(years=1, months=2, days=10)
-        self.assertEqual(dur.totimedelta(datetime(1998, 2, 25)), timedelta(434))
+        self.assertEqual(dur.totimedelta(datetime(1998, 2, 25)),
+                         timedelta(434))
         # leap year has one day more in february
-        self.assertEqual(dur.totimedelta(datetime(2000, 2, 25)), timedelta(435))
+        self.assertEqual(dur.totimedelta(datetime(2000, 2, 25)),
+                         timedelta(435))
         dur = Duration(months=2)
-        # march is longer than february, but april is shorter than march (cause only one day difference compared to 2)
+        # march is longer than february, but april is shorter than
+        # march (cause only one day difference compared to 2)
         self.assertEqual(dur.totimedelta(datetime(2000, 2, 25)), timedelta(60))
         self.assertEqual(dur.totimedelta(datetime(2001, 2, 25)), timedelta(59))
         self.assertEqual(dur.totimedelta(datetime(2001, 3, 25)), timedelta(61))
@@ -499,7 +503,8 @@ def test_suite():
     Return a test suite containing all test defined above.
     '''
     suite = unittest.TestSuite()
-    for durationstring, (expectation, format, altstr) in PARSE_TEST_CASES.items():
+    for durationstring, (expectation, format,
+                         altstr) in PARSE_TEST_CASES.items():
         suite.addTest(create_parsetestcase(durationstring, expectation,
                                            format, altstr))
     for testdata in MATH_TEST_CASES:
@@ -511,6 +516,7 @@ def test_suite():
     suite.addTest(unittest.TestLoader().loadTestsFromTestCase(DurationTest))
     return suite
 
+
 # load_tests Protocol
 def load_tests(loader, tests, pattern):
     return test_suite()
diff --git a/src/isodate/tests/test_pickle.py b/src/isodate/tests/test_pickle.py
index 952c238..867bc40 100644
--- a/src/isodate/tests/test_pickle.py
+++ b/src/isodate/tests/test_pickle.py
@@ -27,6 +27,7 @@ def test_suite():
     suite.addTest(unittest.TestLoader().loadTestsFromTestCase(TestPickle))
     return suite
 
+
 # load_tests Protocol
 def load_tests(loader, tests, pattern):
     return test_suite()
diff --git a/src/isodate/tests/test_strf.py b/src/isodate/tests/test_strf.py
index c7f1c55..37a135b 100644
--- a/src/isodate/tests/test_strf.py
+++ b/src/isodate/tests/test_strf.py
@@ -42,9 +42,11 @@ TEST_CASES = ((datetime(2012, 12, 25, 13, 30, 0, 0, LOCAL), DT_EXT_COMPLETE,
               (datetime(1999, 12, 25, 13, 30, 0, 0, LOCAL), DT_EXT_COMPLETE,
                "1999-12-25T13:30:00+11:00"),
               # microseconds
-              (datetime(2012, 10, 12, 8, 29, 46, 69178), "%Y-%m-%dT%H:%M:%S.%f",
+              (datetime(2012, 10, 12, 8, 29, 46, 69178),
+               "%Y-%m-%dT%H:%M:%S.%f",
                "2012-10-12T08:29:46.069178"),
-              (datetime(2012, 10, 12, 8, 29, 46, 691780), "%Y-%m-%dT%H:%M:%S.%f",
+              (datetime(2012, 10, 12, 8, 29, 46, 691780),
+               "%Y-%m-%dT%H:%M:%S.%f",
                "2012-10-12T08:29:46.691780"),
               )
 
@@ -65,7 +67,8 @@ def create_testcase(dt, format, expectation):
         # local time zone mock function
         def localtime_mock(self, secs):
             """
-            mock time.localtime so that it always returns a time_struct with tm_idst=1
+            mock time.localtime so that it always returns a time_struct with
+            tm_idst=1
             """
             tt = self.ORIG['localtime'](secs)
             # befor 2000 everything is dst, after 2000 no dst.
@@ -85,8 +88,9 @@ def create_testcase(dt, format, expectation):
             self.ORIG['DSTDIFF'] = tzinfo.DSTDIFF
             self.ORIG['localtime'] = time.localtime
             # ovveride all saved values with fixtures.
-            # calculate LOCAL TZ offset, so that this test runs in every time zone
-            tzinfo.STDOFFSET = timedelta(seconds=36000)  # assume we are in +10:00
+            # calculate LOCAL TZ offset, so that this test runs in
+            # every time zone
+            tzinfo.STDOFFSET = timedelta(seconds=36000)  # assume LOC = +10:00
             tzinfo.DSTOFFSET = timedelta(seconds=39600)  # assume DST = +11:00
             tzinfo.DSTDIFF = tzinfo.DSTOFFSET - tzinfo.STDOFFSET
             time.localtime = self.localtime_mock
@@ -122,9 +126,10 @@ def test_suite():
         suite.addTest(create_testcase(dt, format, expectation))
     return suite
 
+
 # load_tests Protocol
 def load_tests(loader, tests, pattern):
     return test_suite()
-    
+
 if __name__ == '__main__':
     unittest.main(defaultTest='test_suite')
diff --git a/src/isodate/tests/test_time.py b/src/isodate/tests/test_time.py
index cdce704..cc5ec08 100644
--- a/src/isodate/tests/test_time.py
+++ b/src/isodate/tests/test_time.py
@@ -54,36 +54,35 @@ TEST_CASES = [('232050', time(23, 20, 50), TIME_BAS_COMPLETE + TZ_BAS),
               ('23:20,8', time(23, 20, 48), None),
               ('23,3', time(23, 18), None),
               ('232030Z', time(23, 20, 30, tzinfo=UTC),
-                          TIME_BAS_COMPLETE + TZ_BAS),
+               TIME_BAS_COMPLETE + TZ_BAS),
               ('2320Z', time(23, 20, tzinfo=UTC), TIME_BAS_MINUTE + TZ_BAS),
               ('23Z', time(23, tzinfo=UTC), TIME_HOUR + TZ_BAS),
               ('23:20:30Z', time(23, 20, 30, tzinfo=UTC),
-                            TIME_EXT_COMPLETE + TZ_EXT),
+               TIME_EXT_COMPLETE + TZ_EXT),
               ('23:20Z', time(23, 20, tzinfo=UTC), TIME_EXT_MINUTE + TZ_EXT),
               ('152746+0100', time(15, 27, 46,
-                                   tzinfo=FixedOffset(1, 0, '+0100')),
-                              TIME_BAS_COMPLETE + TZ_BAS),
+               tzinfo=FixedOffset(1, 0, '+0100')), TIME_BAS_COMPLETE + TZ_BAS),
               ('152746-0500', time(15, 27, 46,
                                    tzinfo=FixedOffset(-5, 0, '-0500')),
-                              TIME_BAS_COMPLETE + TZ_BAS),
+               TIME_BAS_COMPLETE + TZ_BAS),
               ('152746+01', time(15, 27, 46,
                                  tzinfo=FixedOffset(1, 0, '+01:00')),
-                            TIME_BAS_COMPLETE + TZ_HOUR),
+               TIME_BAS_COMPLETE + TZ_HOUR),
               ('152746-05', time(15, 27, 46,
                                  tzinfo=FixedOffset(-5, -0, '-05:00')),
-                            TIME_BAS_COMPLETE + TZ_HOUR),
+               TIME_BAS_COMPLETE + TZ_HOUR),
               ('15:27:46+01:00', time(15, 27, 46,
                                       tzinfo=FixedOffset(1, 0, '+01:00')),
-                                 TIME_EXT_COMPLETE + TZ_EXT),
+               TIME_EXT_COMPLETE + TZ_EXT),
               ('15:27:46-05:00', time(15, 27, 46,
                                       tzinfo=FixedOffset(-5, -0, '-05:00')),
-                                 TIME_EXT_COMPLETE + TZ_EXT),
+               TIME_EXT_COMPLETE + TZ_EXT),
               ('15:27:46+01', time(15, 27, 46,
                                    tzinfo=FixedOffset(1, 0, '+01:00')),
-                              TIME_EXT_COMPLETE + TZ_HOUR),
+               TIME_EXT_COMPLETE + TZ_HOUR),
               ('15:27:46-05', time(15, 27, 46,
                                    tzinfo=FixedOffset(-5, -0, '-05:00')),
-                              TIME_EXT_COMPLETE + TZ_HOUR),
+               TIME_EXT_COMPLETE + TZ_HOUR),
               ('1:17:30', None, TIME_EXT_COMPLETE)]
 
 
@@ -135,7 +134,8 @@ def test_suite():
         suite.addTest(create_testcase(timestring, expectation, format))
     return suite
 
- # load_tests Protocol
+
+# load_tests Protocol
 def load_tests(loader, tests, pattern):
     return test_suite()
 
diff --git a/src/isodate/tzinfo.py b/src/isodate/tzinfo.py
index 820c88d..b41f058 100644
--- a/src/isodate/tzinfo.py
+++ b/src/isodate/tzinfo.py
@@ -9,6 +9,7 @@ import time
 ZERO = timedelta(0)
 # constant for zero time offset.
 
+
 class Utc(tzinfo):
     '''UTC
 
@@ -23,19 +24,22 @@ class Utc(tzinfo):
 
     def tzname(self, dt):
         '''
-        Return the time zone name corresponding to the datetime object dt, as a string.
+        Return the time zone name corresponding to the datetime object dt,
+        as a string.
         '''
         return "UTC"
 
     def dst(self, dt):
         '''
-        Return the daylight saving time (DST) adjustment, in minutes east of UTC.
+        Return the daylight saving time (DST) adjustment, in minutes east
+        of UTC.
         '''
         return ZERO
 
 UTC = Utc()
 # the default instance for UTC.
 
+
 class FixedOffset(tzinfo):
     '''
     A class building tzinfo objects for fixed-offset time zones.
@@ -80,18 +84,19 @@ class FixedOffset(tzinfo):
         return "<FixedOffset %r>" % self.__name
 
 
-STDOFFSET = timedelta(seconds = -time.timezone)
+STDOFFSET = timedelta(seconds=-time.timezone)
 # locale time zone offset
 
 # calculate local daylight saving offset if any.
 if time.daylight:
-    DSTOFFSET = timedelta(seconds = -time.altzone)
+    DSTOFFSET = timedelta(seconds=-time.altzone)
 else:
     DSTOFFSET = STDOFFSET
 
 DSTDIFF = DSTOFFSET - STDOFFSET
 # difference between local time zone and local DST time zone
 
+
 class LocalTimezone(tzinfo):
     """
     A class capturing the platform's idea of local time.