minor typos

IPython/nbconvert/tests/base.py

@@ -1,139 +1,138 b''
 """
 Contains base test class for nbconvert
 """
 #-----------------------------------------------------------------------------
 #Copyright (c) 2013, the IPython Development Team.
 #
 #Distributed under the terms of the Modified BSD License.
 #
 #The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 import os
 import glob
 import shutil
 
 import IPython
 from IPython.utils.tempdir import TemporaryWorkingDirectory
 from IPython.utils.process import get_output_error_code
 from IPython.testing.tools import get_ipython_cmd
 
 # a trailing space allows for simpler concatenation with the other arguments
 ipy_cmd = get_ipython_cmd(as_string=True) + " "
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 
 class TestsBase(object):
-    """Base tests class.  Contains usefull fuzzy comparison and nbconvert
+    """Base tests class.  Contains useful fuzzy comparison and nbconvert
     functions."""
 
 
     def fuzzy_compare(self, a, b, newlines_are_spaces=True, tabs_are_spaces=True, 
                       fuzzy_spacing=True, ignore_spaces=False, 
                       ignore_newlines=False, case_sensitive=False):
         """
         Performs a fuzzy comparison of two strings.  A fuzzy comparison is a
         comparison that ignores insignificant differences in the two comparands.
         The significance of certain differences can be specified via the keyword
         parameters of this method.
         """
 
         if newlines_are_spaces:
             a = a.replace('\n', ' ')
             b = b.replace('\n', ' ')
 
         if tabs_are_spaces:
             a = a.replace('\t', ' ')
             b = b.replace('\t', ' ')
 
         if ignore_spaces:
             a = a.replace(' ', '')
             b = b.replace(' ', '')
 
         if fuzzy_spacing:
             a = self.recursive_replace(a, '  ', ' ')
             b = self.recursive_replace(b, '  ', ' ')
 
         if ignore_newlines:
             a = a.replace('\n', '')
             b = b.replace('\n', '')
 
         if not case_sensitive:
             a = a.lower()
             b = b.lower()
 
         return a == b
 
 
     def recursive_replace(self, text, search, replacement):
         """
         Performs a recursive replacement operation.  Replaces all instances
         of a search string in a text string with a replacement string until
         the search string no longer exists.  Recursion is needed because the
         replacement string may generate additional search strings.
 
         For example:
            Replace "ii" with "i" in the string "Hiiii" yields "Hii"
            Another replacement yields "Hi" (the desired output)
 
         Parameters:
         -----------
         text : string
             Text to replace in.
         search : string
             String to search for within "text"
         replacement : string
             String to replace "search" with
         """
         while search in text:
             text = text.replace(search, replacement)
         return text
 
-            
     def create_temp_cwd(self, copy_filenames=None):
         temp_dir = TemporaryWorkingDirectory()
 
         #Copy the files if requested.
-        if not copy_filenames is None:
+        if copy_filenames is not None:
             self.copy_files_to(copy_filenames)
 
         #Return directory handler
         return temp_dir
 
 
     def copy_files_to(self, copy_filenames, dest='.'):
         "Copy test files into the destination directory"
         if not os.path.isdir(dest):
             os.makedirs(dest)
         files_path = self._get_files_path()
         for pattern in copy_filenames:
             for match in glob.glob(os.path.join(files_path, pattern)):
                 shutil.copyfile(match, os.path.join(dest, os.path.basename(match)))
 
 
     def _get_files_path(self):
 
         #Get the relative path to this module in the IPython directory.
         names = self.__module__.split('.')[1:-1]
         names.append('files')
         
         #Build a path using the IPython directory and the relative path we just
         #found.
         path = IPython.__path__[0]
         for name in names:
             path = os.path.join(path, name)
         return path
 
 
     def call(self, parameters, raise_on_error=True):
         stdout, stderr, retcode = get_output_error_code(ipy_cmd + parameters)
         if retcode != 0 and raise_on_error:
             raise OSError(stderr)
         return stdout, stderr