Add '-not' flag for excluding tags from filter

Add tests for the excluding tags with -not

features/tagging.feature

@@ -50,3 +50,35 @@ Feature: Tagging
             @foo                 : 1
             @bar                 : 1
             """
+
+    Scenario:  Excluding a tag should filter it
+        Given we use the config "basic.yaml"
+        When we run "jrnl today: @foo came over, we went to a bar"
+        When we run "jrnl I have decided I did not enjoy that @bar"
+        When we run "jrnl --tags -not @bar"
+        Then the output should be
+            """
+            @foo                 : 1
+            """
+
+    Scenario:  Excluding a tag should filter an entry, even if an unfiltered tag is in that entry
+        Given we use the config "basic.yaml"
+        When we run "jrnl today: I do @not think this will show up @thought"
+        When we run "jrnl today: I think this will show up @thought"
+        When we run "jrnl --tags -not @not"
+        Then the output should be
+            """
+            @thought             : 1
+            """
+
+    Scenario:  Excluding multiple tags should filter them
+        Given we use the config "basic.yaml"
+        When we run "jrnl today: I do @not think this will show up @thought"
+        When we run "jrnl today: I think this will show up @thought"
+        When we run "jrnl today: This should @never show up @thought"
+        When we run "jrnl today: What a nice day for filtering @thought"
+        When we run "jrnl --tags -not @not @never"
+        Then the output should be
+            """
+            @thought             : 2
+            """

jrnl/Journal.py

@@ -186,7 +186,7 @@ class Journal(object):
         tag_counts = set([(tags.count(tag), tag) for tag in tags])
         return [Tag(tag, count=count) for count, tag in sorted(tag_counts)]
 
-    def filter(self, tags=[], start_date=None, end_date=None, starred=False, strict=False, short=False):
+    def filter(self, tags=[], start_date=None, end_date=None, starred=False, strict=False, short=False, exclude=[]):
         """Removes all entries from the journal that don't match the filter.
 
         tags is a list of tags, each being a string that starts with one of the
@@ -197,19 +197,24 @@ class Journal(object):
         starred limits journal to starred entries
 
         If strict is True, all tags must be present in an entry. If false, the
-        entry is kept if any tag is present."""
+
+        exclude is a list of the tags which should not appear in the results.
+        entry is kept if any tag is present, unless they appear in exclude."""
         self.search_tags = set([tag.lower() for tag in tags])
+        excluded_tags = set([tag.lower() for tag in exclude])
         end_date = time.parse(end_date, inclusive=True)
         start_date = time.parse(start_date)
 
         # If strict mode is on, all tags have to be present in entry
         tagged = self.search_tags.issubset if strict else self.search_tags.intersection
+        excluded = lambda tags: len([tag for tag in tags if tag in excluded_tags]) > 0
         result = [
             entry for entry in self.entries
             if (not tags or tagged(entry.tags))
             and (not starred or entry.starred)
             and (not start_date or entry.date >= start_date)
             and (not end_date or entry.date <= end_date)
+            and (not exclude or not excluded(entry.tags))
         ]
 
         self.entries = result

jrnl/cli.py

@@ -39,6 +39,7 @@ def parse_args(args=None):
     reading.add_argument('-and', dest='strict', action="store_true", help='Filter by tags using AND (default: OR)')
     reading.add_argument('-starred', dest='starred', action="store_true", help='Show only starred entries')
     reading.add_argument('-n', dest='limit', default=None, metavar="N", help="Shows the last n entries matching the filter. '-n 3' and '-3' have the same effect.", nargs="?", type=int)
+    reading.add_argument('-not', dest='excluded', nargs='+', default=[], metavar="E", help="Exclude entries with these tags")
 
     exporting = parser.add_argument_group('Export / Import', 'Options for transmogrifying your journal')
     exporting.add_argument('-s', '--short', dest='short', action="store_true", help='Show only titles or line containing the search tags')
@@ -239,7 +240,8 @@ def run(manual_args=None):
                        start_date=args.start_date, end_date=args.end_date,
                        strict=args.strict,
                        short=args.short,
-                       starred=args.starred)
+                       starred=args.starred,
+                       exclude=args.excluded)
         journal.limit(args.limit)
 
     # Reading mode