diff --git a/docs/conf.py b/docs/conf.py
index c903aa0..8426262 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -16,225 +16,227 @@
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-sys.path.insert(0, os.path.abspath('..'))
+sys.path.insert(0, os.path.abspath(".."))
 
 MOCK_MODULES = []
-if os.environ.get('READTHEDOCS', None) == 'True':
-    print('READTHEDOCS')
+if os.environ.get("READTHEDOCS", None) == "True":
+    print("READTHEDOCS")
     import mock
-    MOCK_MODULES = ['matplotlib', 'matplotlib.pyplot', 'matplotlib.tight_layout', 
-                'mpl_toolkits', 'mpl_toolkits.axisartist',
-                'numpy', 'pandas']
+
+    MOCK_MODULES = [
+        "matplotlib",
+        "matplotlib.pyplot",
+        "matplotlib.tight_layout",
+        "mpl_toolkits",
+        "mpl_toolkits.axisartist",
+        "numpy",
+        "pandas",
+    ]
 for mod_name in MOCK_MODULES:
     sys.modules[mod_name] = mock.Mock()
 
 # -- General configuration -----------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-#needs_sphinx = '1.0'
+# needs_sphinx = '1.0'
 
 # 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.autodoc', 'sphinx.ext.intersphinx', 'sphinx.ext.mathjax']
-if not os.environ.get('READTHEDOCS', None) == 'True':
-    extensions.append('sphinx.ext.napoleon')
+extensions = ["sphinx.ext.autodoc", "sphinx.ext.intersphinx", "sphinx.ext.mathjax"]
+if not os.environ.get("READTHEDOCS", None) == "True":
+    extensions.append("sphinx.ext.napoleon")
 numpydoc_show_class_members = False
 
 # 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'pyblock'
-copyright = u'2014, James Spencer'
+project = "pyblock"
+copyright = "2014, James Spencer"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 #
 # The short X.Y version.
-version = '0.4'
+version = "0.4"
 # The full version, including alpha/beta/rc tags.
-release = '0.4'
+release = "0.4"
 
 # 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 = ['_build']
+exclude_patterns = ["_build"]
 
 # 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 = []
 
 # -- Options for HTML output ---------------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 import os
-if os.environ.get('READTHEDOCS', None) == 'True':
-    html_theme = 'default'
+
+if os.environ.get("READTHEDOCS", None) == "True":
+    html_theme = "default"
 else:
-    html_theme = 'pyramid'
+    html_theme = "pyramid"
 
 # 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 = []
+# 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 = None
+# html_short_title = None
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-#html_logo = None
+# html_logo = None
 
 # 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 = None
+# html_favicon = None
 
 # 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 = 'pyblockdoc'
+htmlhelp_basename = "pyblockdoc"
 
 
 # -- Options for LaTeX output --------------------------------------------------
 
 latex_elements = {
-# The paper size ('letterpaper' or 'a4paper').
-#'papersize': 'letterpaper',
-
-# The font size ('10pt', '11pt' or '12pt').
-#'pointsize': '10pt',
-
-# Additional stuff for the LaTeX preamble.
-#'preamble': '',
+    # The paper size ('letterpaper' or 'a4paper').
+    #'papersize': 'letterpaper',
+    # The font size ('10pt', '11pt' or '12pt').
+    #'pointsize': '10pt',
+    # Additional stuff for the LaTeX preamble.
+    #'preamble': '',
 }
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-  ('index', 'pyblock.tex', u'pyblock Documentation',
-   u'James Spencer', 'manual'),
+    ("index", "pyblock.tex", "pyblock Documentation", "James Spencer", "manual"),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
-#latex_logo = None
+# latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
-#latex_use_parts = False
+# latex_use_parts = False
 
 # If true, show page references after internal links.
-#latex_show_pagerefs = False
+# latex_show_pagerefs = False
 
 # If true, show URL addresses after external links.
-#latex_show_urls = False
+# latex_show_urls = False
 
 # Documents to append as an appendix to all manuals.
-#latex_appendices = []
+# latex_appendices = []
 
 # If false, no module index is generated.
-#latex_domain_indices = True
+# latex_domain_indices = True
 
 
 # -- Options for manual page output --------------------------------------------
 
 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
-man_pages = [
-    ('index', 'pyblock', u'pyblock Documentation',
-     [u'James Spencer'], 1)
-]
+man_pages = [("index", "pyblock", "pyblock Documentation", ["James Spencer"], 1)]
 
 # If true, show URL addresses after external links.
-#man_show_urls = False
+# man_show_urls = False
 
 
 # -- Options for Texinfo output ------------------------------------------------
@@ -243,24 +245,34 @@
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-  ('index', 'pyblock', u'pyblock Documentation',
-   u'James Spencer', 'pyblock', 'One line description of project.',
-   'Miscellaneous'),
+    (
+        "index",
+        "pyblock",
+        "pyblock Documentation",
+        "James Spencer",
+        "pyblock",
+        "One line description of project.",
+        "Miscellaneous",
+    ),
 ]
 
 # Documents to append as an appendix to all manuals.
-#texinfo_appendices = []
+# texinfo_appendices = []
 
 # If false, no module index is generated.
-#texinfo_domain_indices = True
+# texinfo_domain_indices = True
 
 # How to display URL addresses: 'footnote', 'no', or 'inline'.
-#texinfo_show_urls = 'footnote'
+# texinfo_show_urls = 'footnote'
 
 
 # Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {'python': ('http://docs.python.org/2.7', None),
-                       'numpy':('http://docs.scipy.org/doc/numpy', 'http://docs.scipy.org/doc/numpy/objects.inv'),
-                       'pandas': ('http://pandas.pydata.org/pandas-docs/stable/', None),
-                       'matplotlib':('http://matplotlib.sourceforge.net', None),
-                      }
+intersphinx_mapping = {
+    "python": ("http://docs.python.org/2.7", None),
+    "numpy": (
+        "http://docs.scipy.org/doc/numpy",
+        "http://docs.scipy.org/doc/numpy/objects.inv",
+    ),
+    "pandas": ("http://pandas.pydata.org/pandas-docs/stable/", None),
+    "matplotlib": ("http://matplotlib.sourceforge.net", None),
+}
diff --git a/pyblock/tests/test_pd_utils.py b/pyblock/tests/test_pd_utils.py
index 9d841d5..8d6d973 100644
--- a/pyblock/tests/test_pd_utils.py
+++ b/pyblock/tests/test_pd_utils.py
@@ -59,9 +59,9 @@ def test_pdblock_opt(self):
         self.assertEqual(
             pyblock.pd_utils.optimal_block(reblock), tests_base.reblock_1D_opt[0]
         )
-        reblock.loc[
-            tests_base.reblock_1D_opt[0] - 1, ("data", "optimal block")
-        ] = "<---"
+        reblock.loc[tests_base.reblock_1D_opt[0] - 1, ("data", "optimal block")] = (
+            "<---"
+        )
         with self.assertRaises(ValueError):
             pyblock.pd_utils.optimal_block(reblock)
         reblock[("data", "optimal block")] = ""