Show "More by" on author page

Uses Goodread's list of author's books, filtering out the books that are already in the user's library.

Requires the Goodreads dependency and API information.

cps/web.py

@@ -8,11 +8,16 @@ except ImportError:
     gdrive_support = False
 
 try:
-    from goodreads import client as gr_client
+    from goodreads.client import GoodreadsClient
     goodreads_support = True
 except ImportError:
     goodreads_support = False
 
+try:
+    from functools import reduce
+except ImportError:
+    pass  # We're not using Python 3
+
 import mimetypes
 import logging
 from logging.handlers import RotatingFileHandler
@@ -1167,20 +1172,27 @@ def author_list():
 def author(book_id, page):
     entries, random, pagination = fill_indexpage(page, db.Books, db.Books.authors.any(db.Authors.id == book_id),
                                                  db.Books.timestamp.desc())
-    if entries:
-        name = db.session.query(db.Authors).filter(db.Authors.id == book_id).first().name
-
-        author_info = None
-        if goodreads_support and config.config_use_goodreads:
-            gc = gr_client.GoodreadsClient(config.config_goodreads_api_key, config.config_goodreads_api_secret)
-            author_info = gc.find_author(author_name=name)
-
-        return render_title_template('author.html', entries=entries, pagination=pagination,
-                                     title=name, author=author_info)
-    else:
+    if entries is None:
         flash(_(u"Error opening eBook. File does not exist or file is not accessible:"), category="error")
         return redirect(url_for("index"))
 
+    name = db.session.query(db.Authors).filter(db.Authors.id == book_id).first().name
+
+    author_info = None
+    other_books = None
+    if goodreads_support and config.config_use_goodreads:
+        gc = GoodreadsClient(config.config_goodreads_api_key, config.config_goodreads_api_secret)
+        author_info = gc.find_author(author_name=name)
+
+        # Get all identifiers (ISBN, Goodreads, etc) and filter author's books by that list so we show fewer duplicates
+        # Note: Not all images will be shown, even though they're available on Goodreads.com.
+        #       See https://www.goodreads.com/topic/show/18213769-goodreads-book-images
+        identifiers = reduce(lambda acc, book: acc + map(lambda identifier: identifier.val, book.identifiers), entries.all(), [])
+        other_books = filter(lambda book: book.isbn not in identifiers and book.gid["#text"] not in identifiers, author_info.books)
+
+    return render_title_template('author.html', entries=entries, pagination=pagination,
+                                 title=name, author=author_info, other_books=other_books)
+
 
 @app.route("/series")
 @login_required_if_no_ano