diff --git a/conda/meta.yaml b/conda/meta.yaml
index 6250242cefc4bbd94d530964896e8a0b02cc7957..5c59fcf37b411865ee614460b60ada1aeecd25fb 100644
--- a/conda/meta.yaml
+++ b/conda/meta.yaml
@@ -61,8 +61,8 @@ test:
     # runs tests for package only, report only what is in the package
     # creates html and xml reports and place them in specific directories
     - pytest --verbose --cov {{ name }} --cov-report term-missing --cov-report html:{{ project_dir }}/sphinx/coverage --cov-report xml:{{ project_dir }}/coverage.xml --pyargs {{ name }}
-    - sphinx-build -aEW {{ project_dir }}/doc {{ project_dir }}/sphinx
-    - sphinx-build -aEb doctest {{ project_dir }}/doc sphinx
+    - sphinx-build -aEW {{ project_dir }}/doc {{ project_dir }}/sphinx # [linux]
+    - sphinx-build -aEb doctest {{ project_dir }}/doc sphinx # [linux]
     - conda inspect linkages -p $PREFIX {{ name }}  # [not win]
     - conda inspect objects -p $PREFIX {{ name }}  # [osx]
   requires:
diff --git a/doc/conf.py b/doc/conf.py
index cc6627616e420fec5db36ff5807f2808f668accb..0da76cc48cb324514096368bce4f31784c14cd61 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -10,24 +10,24 @@ import pkg_resources
 # -- General configuration -----------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-needs_sphinx = '1.3'
+needs_sphinx = "1.3"
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 extensions = [
-    'sphinx.ext.todo',
-    'sphinx.ext.coverage',
-    'sphinx.ext.ifconfig',
-    'sphinx.ext.autodoc',
-    'sphinx.ext.autosummary',
-    'sphinx.ext.doctest',
-    'sphinx.ext.graphviz',
-    'sphinx.ext.intersphinx',
-    'sphinx.ext.napoleon',
-    'sphinx.ext.viewcode',
-    'sphinx.ext.mathjax',
-    'matplotlib.sphinxext.plot_directive'
-    ]
+    "sphinx.ext.todo",
+    "sphinx.ext.coverage",
+    "sphinx.ext.ifconfig",
+    "sphinx.ext.autodoc",
+    "sphinx.ext.autosummary",
+    "sphinx.ext.doctest",
+    "sphinx.ext.graphviz",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.napoleon",
+    "sphinx.ext.viewcode",
+    "sphinx.ext.mathjax",
+    "matplotlib.sphinxext.plot_directive",
+]
 
 # Be picky about warnings
 nitpicky = False
@@ -36,13 +36,13 @@ nitpicky = False
 nitpick_ignore = []
 
 # Allows the user to override warnings from a separate file
-if os.path.exists('nitpick-exceptions.txt'):
-    for line in open('nitpick-exceptions.txt'):
+if os.path.exists("nitpick-exceptions.txt"):
+    for line in open("nitpick-exceptions.txt"):
         if line.strip() == "" or line.startswith("#"):
             continue
         dtype, target = line.split(None, 1)
         target = target.strip()
-        try: # python 2.x
+        try:  # python 2.x
             target = unicode(target)
         except NameError:
             pass
@@ -58,25 +58,27 @@ autosummary_generate = True
 numfig = True
 
 # If we are on OSX, the 'dvipng' path maybe different
-dvipng_osx = '/opt/local/libexec/texlive/binaries/dvipng'
-if os.path.exists(dvipng_osx): pngmath_dvipng = dvipng_osx
+dvipng_osx = "/opt/local/libexec/texlive/binaries/dvipng"
+if os.path.exists(dvipng_osx):
+    pngmath_dvipng = dvipng_osx
 
 # Add any paths that contain templates here, relative to this directory.
-templates_path = ['_templates']
+templates_path = ["_templates"]
 
 # The suffix of source filenames.
-source_suffix = '.rst'
+source_suffix = ".rst"
 
 # The encoding of source files.
-#source_encoding = 'utf-8-sig'
+# source_encoding = 'utf-8-sig'
 
 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"
 
 # General information about the project.
-project = u'bob.bio.face'
+project = u"bob.bio.face"
 import time
-copyright = u'%s, Idiap Research Institute' % time.strftime('%Y')
+
+copyright = u"%s, Idiap Research Institute" % time.strftime("%Y")
 
 # Grab the setup entry
 distribution = pkg_resources.require(project)[0]
@@ -92,42 +94,42 @@ release = distribution.version
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-#language = None
+# language = None
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
-#today = ''
+# today = ''
 # Else, today_fmt is used as the format for a strftime call.
-#today_fmt = '%B %d, %Y'
+# today_fmt = '%B %d, %Y'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
-exclude_patterns = ['links.rst']
+exclude_patterns = ["links.rst"]
 
 # The reST default role (used for this markup: `text`) to use for all documents.
-#default_role = None
+# default_role = None
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
-#add_function_parentheses = True
+# add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
-#add_module_names = True
+# add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
-#show_authors = False
+# show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'sphinx'
+pygments_style = "sphinx"
 
 # A list of ignored prefixes for module index sorting.
-#modindex_common_prefix = []
+# modindex_common_prefix = []
 
 # Some variables which are useful for generated material
-project_variable = project.replace('.', '_')
-short_description = u'Tools for running face recognition experiments'
-owner = [u'Idiap Research Institute']
+project_variable = project.replace(".", "_")
+short_description = u"Tools for running face recognition experiments"
+owner = [u"Idiap Research Institute"]
 
 
 # -- Options for HTML output ---------------------------------------------------
@@ -135,80 +137,81 @@ owner = [u'Idiap Research Institute']
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 import sphinx_rtd_theme
-html_theme = 'sphinx_rtd_theme'
+
+html_theme = "sphinx_rtd_theme"
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
-#html_theme_options = {}
+# html_theme_options = {}
 
 # Add any paths that contain custom themes here, relative to this directory.
 html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
-#html_title = None
+# html_title = None
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
-#html_short_title = project_variable
+# html_short_title = project_variable
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-html_logo = 'img/logo.png'
+html_logo = "img/logo.png"
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-html_favicon = 'img/favicon.ico'
+html_favicon = "img/favicon.ico"
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-#html_static_path = ['_static']
+# html_static_path = ['_static']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
-#html_last_updated_fmt = '%b %d, %Y'
+# html_last_updated_fmt = '%b %d, %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
-#html_use_smartypants = True
+# html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
+# html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
-#html_additional_pages = {}
+# html_additional_pages = {}
 
 # If false, no module index is generated.
-#html_domain_indices = True
+# html_domain_indices = True
 
 # If false, no index is generated.
-#html_use_index = True
+# html_use_index = True
 
 # If true, the index is split into individual pages for each letter.
-#html_split_index = False
+# html_split_index = False
 
 # If true, links to the reST sources are added to the pages.
-#html_show_sourcelink = True
+# html_show_sourcelink = True
 
 # If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
-#html_show_sphinx = True
+# html_show_sphinx = True
 
 # If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
-#html_show_copyright = True
+# html_show_copyright = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-#html_use_opensearch = ''
+# html_use_opensearch = ''
 
 # This is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = None
+# html_file_suffix = None
 
 # Output file base name for HTML help builder.
-htmlhelp_basename = project_variable + u'_doc'
+htmlhelp_basename = project_variable + u"_doc"
 
 
 # -- Post configuration --------------------------------------------------------
@@ -218,26 +221,26 @@ rst_epilog = """
 .. |project| replace:: Bob
 .. |version| replace:: %s
 .. |current-year| date:: %%Y
-""" % (version,)
+""" % (
+    version,
+)
 
 # Default processing flags for sphinx
-autoclass_content = 'class'
-autodoc_member_order = 'bysource'
+autoclass_content = "class"
+autodoc_member_order = "bysource"
 autodoc_default_options = {
-  "members": True,
-  "undoc-members": True,
-  "show-inheritance": True,
+    "members": True,
+    "undoc-members": True,
+    "show-inheritance": True,
 }
 
 # For inter-documentation mapping:
 from bob.extension.utils import link_documentation, load_requirements
+
 sphinx_requirements = "extra-intersphinx.txt"
 if os.path.exists(sphinx_requirements):
-  intersphinx_mapping = link_documentation(
-      additional_packages=['python','numpy'] + \
-          load_requirements(sphinx_requirements)
-          )
+    intersphinx_mapping = link_documentation(
+        additional_packages=["python", "numpy"] + load_requirements(sphinx_requirements)
+    )
 else:
-  intersphinx_mapping = link_documentation()
-
-
+    intersphinx_mapping = link_documentation()
diff --git a/doc/implemented.rst b/doc/implemented.rst
index 313fa086f721c95bd2b94cf86f463c5fda9077b6..4e3d967d5822412c9f8266d2c95af6b4aebf02d7 100644
--- a/doc/implemented.rst
+++ b/doc/implemented.rst
@@ -9,7 +9,6 @@ Summary
 
 Databases
 ~~~~~~~~~
-
 .. autosummary::
    bob.bio.face.database.ARFaceBioDatabase
    bob.bio.face.database.AtntBioDatabase