Use Post class attributes in filename-pattern

- Added owner_id and mediaid to Post class properties.
- In case of not downloading stories, the attributes of the Post class
  can now be used in filename-pattern, e.g. {post.owner_id} or {post.mediaid}.

Closes #53.

docs/README.md

@@ -10,6 +10,6 @@ https://instaloader.readthedocs.io/
 The documentation is created with [Sphinx](http://www.sphinx-doc.org/). To build it, use
 
 ```
-pip3 install sphinx
+pip3 install sphinx sphinx-autodoc-typehints
 make html
 ```

docs/basic-usage.rst

@@ -96,7 +96,8 @@ pattern, the token ``{target}`` is replaced by the target name, and
 to the target directory. The default is ``--filename-pattern={date}``.
 The tokens ``{target}`` and ``{profile}`` are replaced like in the
 dirname pattern. Further, the tokens ``{date}`` and ``{shortcode}`` are
-defined.
+defined. Additionally, in case of not downloading stories, the attributes of
+:class:`.Post` can be used, e.g. ``{post.owner_id}`` or ``{post.mediaid}``.
 
 For example, encode the poster's profile name in the filenames with:
 

docs/cli-options.rst

@@ -134,8 +134,11 @@ How to Download
    with ``--dirname-pattern``.  ``{profile}`` is replaced by the profile name,
    ``{target}`` is replaced by the target you specified, i.e.  either ``:feed``,
    ``#hashtag`` or the profile name.  Also, the fields ``{date}`` and
-   ``{shortcode}`` can be specified.  Defaults to ``{date:%Y-%m-%d_%H-%M-%S}``.
+   ``{shortcode}`` can be specified.  In case of not downloading stories, the
-   See :ref:`filename-specification`.
+   attributes of the :class:`.Post` class can be used in addition, e.g.
+   ``{post.owner_id}`` or ``{post.mediaid}``.
+   Defaults to
+   ``{date:%Y-%m-%d_%H-%M-%S}``.  See :ref:`filename-specification`.
 
 .. option:: --user-agent USER_AGENT
 

instaloader.py

@@ -126,7 +126,7 @@ def mediaid_to_shortcode(mediaid: int) -> str:
 def format_string_contains_key(format_string: str, key: str) -> bool:
     # pylint:disable=unused-variable
     for literal_text, field_name, format_spec, conversion in string.Formatter().parse(format_string):
-        if field_name == key:
+        if field_name == key or field_name.startswith(key + '.'):
             return True
     return False
 
@@ -176,7 +176,8 @@ class Post:
 
     LOGIN_REQUIRING_PROPERTIES = ["viewer_has_liked"]
 
-    def __init__(self, instaloader: 'Instaloader', node: Dict[str, Any], profile: Optional[str] = None):
+    def __init__(self, instaloader: 'Instaloader', node: Dict[str, Any],
+                 profile: Optional[str] = None, profile_id: Optional[int] = None):
         """Create a Post instance from a node structure as returned by Instagram.
 
         :param instaloader: :class:`Instaloader` instance used for additional queries if neccessary.
@@ -186,6 +187,7 @@ class Post:
         self._instaloader = instaloader
         self._node = node
         self._profile = profile
+        self._profile_id = profile_id
         self._full_metadata_dict = None
 
     @classmethod
@@ -206,6 +208,11 @@ class Post:
         """Media shortcode. URL of the post is instagram.com/p/<shortcode>/."""
         return self._node['shortcode'] if 'shortcode' in self._node else self._node['code']
 
+    @property
+    def mediaid(self) -> int:
+        """The mediaid is a decimal representation of the media shortcode."""
+        return int(self._node['id'])
+
     def __repr__(self):
         return '<Post {}>'.format(self.shortcode)
 
@@ -252,6 +259,13 @@ class Post:
             self._instaloader.error("Get owner name of {}: {} -- using \'UNKNOWN\'.".format(self, err))
             return 'UNKNOWN'
 
+    @property
+    def owner_id(self) -> int:
+        """The ID of the Post's owner."""
+        if self._profile_id:
+            return self._profile_id
+        return int(self._field('owner', 'id'))
+
     @property
     def date(self) -> datetime:
         """Timestamp when the post was created."""
@@ -889,7 +903,8 @@ class Instaloader:
         profilename = post.owner_username if needs_profilename else None
         dirname = self.dirname_pattern.format(profile=profilename, target=target.lower())
         filename = dirname + '/' + self.filename_pattern.format(profile=profilename, target=target.lower(),
-                                                                date=post.date, shortcode=post.shortcode)
+                                                                date=post.date, shortcode=post.shortcode,
+                                                                post=post)
         os.makedirs(os.path.dirname(filename), exist_ok=True)
 
         # Download the image(s) / video thumbnail and videos within sidecars if desired
@@ -993,6 +1008,10 @@ class Instaloader:
         :param filename_target: Replacement for {target} in dirname_pattern and filename_pattern
         """
 
+        if format_string_contains_key(self.filename_pattern, 'post'):
+            raise InvalidArgumentException("The \"post\" keyword is not supported in the filename pattern when "
+                                           "downloading stories.")
+
         if not self.is_logged_in:
             raise LoginRequiredException('Login required to download stories')
 
@@ -1202,7 +1221,9 @@ class Instaloader:
     def get_profile_posts(self, profile_metadata: Dict[str, Any]) -> Iterator[Post]:
         """Retrieve all posts from a profile."""
         profile_name = profile_metadata['user']['username']
-        yield from (Post(self, node, profile=profile_name) for node in profile_metadata['user']['media']['nodes'])
+        profile_id = int(profile_metadata['user']['id'])
+        yield from (Post(self, node, profile=profile_name, profile_id=profile_id)
+                    for node in profile_metadata['user']['media']['nodes'])
         has_next_page = profile_metadata['user']['media']['page_info']['has_next_page']
         end_cursor = profile_metadata['user']['media']['page_info']['end_cursor']
         while has_next_page:
@@ -1213,7 +1234,8 @@ class Instaloader:
                                                           'after': end_cursor},
                                       'https://www.instagram.com/{0}/'.format(profile_name))
             media = data['data']['user']['edge_owner_to_timeline_media']
-            yield from (Post(self, edge['node'], profile=profile_name) for edge in media['edges'])
+            yield from (Post(self, edge['node'], profile=profile_name, profile_id=profile_id)
+                        for edge in media['edges'])
             has_next_page = media['page_info']['has_next_page']
             end_cursor = media['page_info']['end_cursor']
 
@@ -1468,8 +1490,9 @@ def main():
                        help='Prefix of filenames. Posts are stored in the directory whose pattern is given with '
                             '--dirname-pattern. {profile} is replaced by the profile name, '
                             '{target} is replaced by the target you specified, i.e. either :feed, #hashtag or the '
-                            'profile name. Also, the fields date and shortcode can be specified. Defaults to '
+                            'profile name. Also, the fields {date} and {shortcode} can be specified. In case of not '
-                            '\'{date:%%Y-%%m-%%d_%%H-%%M-%%S}\'.')
+                            'downloading stories, the attributes of the Post class can be used in addition, e.g. '
+                            '{post.owner_id} or {post.mediaid}. Defaults to \'{date:%%Y-%%m-%%d_%%H-%%M-%%S}\'.')
     g_how.add_argument('--user-agent',
                        help='User Agent to use for HTTP requests. Defaults to \'{}\'.'.format(default_user_agent()))
     g_how.add_argument('-S', '--no-sleep', action='store_true', help=SUPPRESS)