Modernize code to Python 3.6+ and some cleanup

05-record-like/dataclass/coordinates.py

@@ -16,7 +16,7 @@ class Coordinate:
 	
     lat: float
     long: float
-        
+
     def __str__(self):
         ns = 'N' if self.lat >= 0 else 'S'
         we = 'E' if self.long >= 0 else 'W'

05-record-like/dataclass/hackerclub.py

@@ -30,7 +30,7 @@ To fix, ``leo2`` must be created with an explicit ``handle``::
 
 # tag::HACKERCLUB[]
 from dataclasses import dataclass
-from club import ClubMember         
+from club import ClubMember
 
 @dataclass
 class HackerClubMember(ClubMember):                         # <1>

05-record-like/dataclass/hackerclub_annotated.py

@@ -31,7 +31,7 @@ To fix, ``leo2`` must be created with an explicit ``handle``::
 # tag::HACKERCLUB[]
 from dataclasses import dataclass
 from typing import ClassVar, Set
-from club import ClubMember         
+from club import ClubMember
 
 @dataclass
 class HackerClubMember(ClubMember):

05-record-like/dataclass/resource.py

@@ -14,7 +14,7 @@ A complete resource record:
     >>> description = 'Improving the design of existing code'
     >>> book = Resource('978-0-13-475759-9', 'Refactoring, 2nd Edition',
     ...     ['Martin Fowler', 'Kent Beck'], date(2018, 11, 19),
-    ...     ResourceType.BOOK, description, 'EN', 
+    ...     ResourceType.BOOK, description, 'EN',
     ...     ['computer programming', 'OOP'])
     >>> book  # doctest: +NORMALIZE_WHITESPACE
     Resource(identifier='978-0-13-475759-9', title='Refactoring, 2nd Edition',

05-record-like/dataclass/resource_repr.py

@@ -21,7 +21,7 @@ A complete resource record:
     >>> description = 'Improving the design of existing code'
     >>> book = Resource('978-0-13-475759-9', 'Refactoring, 2nd Edition',
     ...     ['Martin Fowler', 'Kent Beck'], date(2018, 11, 19),
-    ...     ResourceType.BOOK, description, 'EN', 
+    ...     ResourceType.BOOK, description, 'EN',
     ...     ['computer programming', 'OOP'])
 
 # tag::DOCTEST[]