An extension for python markdown.
Wraps all images in a lightbox link. lightbox was created by Lokesh Dhakar and provided under the MIT License (see LICENSE in lightbox directory). Lightbox CSS and JS must be included in final html-- this extension will not add those! Copies of the lightbox CSS and JS files are included in this repository in the lightbox folder; alternatively these can be accessed at the lightbox github repo
The extension can either group all images into same lightbox if config option group = True (the default), or make each image have a separate lightbox if config option group = False.
Grouping of images into lightboxes can also be done manually be specifying @{lightbox-name} right after the opening "[" bracket of the image, e.g. 
(or after "[!" if hiding the image... see below)
Hidden images (that appear in lightbox gallery but not in the main page) can be added by adding a "!" right after the opening "[" bracket of the image. If adding a lightbox name using "@{name}" then the "!" goes before the "@".
To install, clone the git repo and use pip install /path/to/repo
Then the extension can be used by doing:
import markdown
from mdlightbox import LightboxImagesExtension
md = markdown.Markdown(extensions=[LightboxImagesExtension(group = True)])
#image with default lightbox name
md.convert('')
#hidden image
md.convert('')
#specified lightbox name
md.convert('')
#hidden image with specified lightbox name
md.convert('')
For use with Flask-Flatpages:
FLATPAGES_MARKDOWN_EXTENSIONS = ['mdlightbox:LightboxImagesExtension']
I don't think it is currently possible with Flask-flatpages to add in configuration options. You can always change the default for 'group' in the source code if you prefer group = False.