Merge pull request #10029 from ivanov/doctest-utils-text

enable and fix doctests for IPython.utils

IPython/testing/iptest.py

@@ -1,431 +1,431 b''
 # -*- coding: utf-8 -*-
 """IPython Test Suite Runner.
 
 This module provides a main entry point to a user script to test IPython
 itself from the command line. There are two ways of running this script:
 
 1. With the syntax `iptest all`.  This runs our entire test suite by
    calling this script (with different arguments) recursively.  This
    causes modules and package to be tested in different processes, using nose
    or trial where appropriate.
 2. With the regular nose syntax, like `iptest -vvs IPython`.  In this form
    the script simply calls nose, but with special command line flags and
    plugins loaded.
 
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 import glob
 from io import BytesIO
 import os
 import os.path as path
 import sys
 from threading import Thread, Lock, Event
 import warnings
 
 import nose.plugins.builtin
 from nose.plugins.xunit import Xunit
 from nose import SkipTest
 from nose.core import TestProgram
 from nose.plugins import Plugin
 from nose.util import safe_str
 
 from IPython import version_info
 from IPython.utils.py3compat import bytes_to_str
 from IPython.utils.importstring import import_item
 from IPython.testing.plugin.ipdoctest import IPythonDoctest
 from IPython.external.decorators import KnownFailure, knownfailureif
 
 pjoin = path.join
 
 
 # Enable printing all warnings raise by IPython's modules
 warnings.filterwarnings('ignore', message='.*Matplotlib is building the font cache.*', category=UserWarning, module='.*')
 warnings.filterwarnings('error', message='.*', category=ResourceWarning, module='.*')
 warnings.filterwarnings('error', message=".*{'config': True}.*", category=DeprecationWarning, module='IPy.*')
 warnings.filterwarnings('default', message='.*', category=Warning, module='IPy.*')
 
 if version_info < (6,):
     # nose.tools renames all things from `camelCase` to `snake_case` which raise an
     # warning with the runner they also import from standard import library. (as of Dec 2015)
     # Ignore, let's revisit that in a couple of years for IPython 6.
     warnings.filterwarnings('ignore', message='.*Please use assertEqual instead', category=Warning, module='IPython.*')
 
 
 # ------------------------------------------------------------------------------
 # Monkeypatch Xunit to count known failures as skipped.
 # ------------------------------------------------------------------------------
 def monkeypatch_xunit():
     try:
         knownfailureif(True)(lambda: None)()
     except Exception as e:
         KnownFailureTest = type(e)
 
     def addError(self, test, err, capt=None):
         if issubclass(err[0], KnownFailureTest):
             err = (SkipTest,) + err[1:]
         return self.orig_addError(test, err, capt)
 
     Xunit.orig_addError = Xunit.addError
     Xunit.addError = addError
 
 #-----------------------------------------------------------------------------
 # Check which dependencies are installed and greater than minimum version.
 #-----------------------------------------------------------------------------
 def extract_version(mod):
     return mod.__version__
 
 def test_for(item, min_version=None, callback=extract_version):
     """Test to see if item is importable, and optionally check against a minimum
     version.
 
     If min_version is given, the default behavior is to check against the
     `__version__` attribute of the item, but specifying `callback` allows you to
     extract the value you are interested in. e.g::
 
         In [1]: import sys
 
         In [2]: from IPython.testing.iptest import test_for
 
         In [3]: test_for('sys', (2,6), callback=lambda sys: sys.version_info)
         Out[3]: True
 
     """
     try:
         check = import_item(item)
     except (ImportError, RuntimeError):
         # GTK reports Runtime error if it can't be initialized even if it's
         # importable.
         return False
     else:
         if min_version:
             if callback:
                 # extra processing step to get version to compare
                 check = callback(check)
 
             return check >= min_version
         else:
             return True
 
 # Global dict where we can store information on what we have and what we don't
 # have available at test run time
 have = {'matplotlib': test_for('matplotlib'),
         'pygments': test_for('pygments'),
         'sqlite3': test_for('sqlite3')}
 
 #-----------------------------------------------------------------------------
 # Test suite definitions
 #-----------------------------------------------------------------------------
 
 test_group_names = ['core',
                     'extensions', 'lib', 'terminal', 'testing', 'utils',
                    ]
 
 class TestSection(object):
     def __init__(self, name, includes):
         self.name = name
         self.includes = includes
         self.excludes = []
         self.dependencies = []
         self.enabled = True
     
     def exclude(self, module):
         if not module.startswith('IPython'):
             module = self.includes[0] + "." + module
         self.excludes.append(module.replace('.', os.sep))
     
     def requires(self, *packages):
         self.dependencies.extend(packages)
     
     @property
     def will_run(self):
         return self.enabled and all(have[p] for p in self.dependencies)
 
 # Name -> (include, exclude, dependencies_met)
 test_sections = {n:TestSection(n, ['IPython.%s' % n]) for n in test_group_names}
 
 
 # Exclusions and dependencies
 # ---------------------------
 
 # core:
 sec = test_sections['core']
 if not have['sqlite3']:
     sec.exclude('tests.test_history')
     sec.exclude('history')
 if not have['matplotlib']:
     sec.exclude('pylabtools'),
     sec.exclude('tests.test_pylabtools')
 
 # lib:
 sec = test_sections['lib']
 sec.exclude('kernel')
 if not have['pygments']:
     sec.exclude('tests.test_lexers')
 # We do this unconditionally, so that the test suite doesn't import
 # gtk, changing the default encoding and masking some unicode bugs.
 sec.exclude('inputhookgtk')
 # We also do this unconditionally, because wx can interfere with Unix signals.
 # There are currently no tests for it anyway.
 sec.exclude('inputhookwx')
 # Testing inputhook will need a lot of thought, to figure out
 # how to have tests that don't lock up with the gui event
 # loops in the picture
 sec.exclude('inputhook')
 
 # testing:
 sec = test_sections['testing']
 # These have to be skipped on win32 because they use echo, rm, cd, etc.
 # See ticket https://github.com/ipython/ipython/issues/87
 if sys.platform == 'win32':
     sec.exclude('plugin.test_exampleip')
     sec.exclude('plugin.dtexample')
 
 # don't run jupyter_console tests found via shim
 test_sections['terminal'].exclude('console')
 
 # extensions:
 sec = test_sections['extensions']
 # This is deprecated in favour of rpy2
 sec.exclude('rmagic')
 # autoreload does some strange stuff, so move it to its own test section
 sec.exclude('autoreload')
 sec.exclude('tests.test_autoreload')
 test_sections['autoreload'] = TestSection('autoreload',
         ['IPython.extensions.autoreload', 'IPython.extensions.tests.test_autoreload'])
 test_group_names.append('autoreload')
 
 
 #-----------------------------------------------------------------------------
 # Functions and classes
 #-----------------------------------------------------------------------------
 
 def check_exclusions_exist():
     from IPython.paths import get_ipython_package_dir
     from warnings import warn
     parent = os.path.dirname(get_ipython_package_dir())
     for sec in test_sections:
         for pattern in sec.exclusions:
             fullpath = pjoin(parent, pattern)
             if not os.path.exists(fullpath) and not glob.glob(fullpath + '.*'):
                 warn("Excluding nonexistent file: %r" % pattern)
 
 
 class ExclusionPlugin(Plugin):
     """A nose plugin to effect our exclusions of files and directories.
     """
     name = 'exclusions'
     score = 3000  # Should come before any other plugins
     
     def __init__(self, exclude_patterns=None):
         """
         Parameters
         ----------
 
         exclude_patterns : sequence of strings, optional
           Filenames containing these patterns (as raw strings, not as regular
           expressions) are excluded from the tests.
         """
         self.exclude_patterns = exclude_patterns or []
         super(ExclusionPlugin, self).__init__()
 
     def options(self, parser, env=os.environ):
         Plugin.options(self, parser, env)
     
     def configure(self, options, config):
         Plugin.configure(self, options, config)
         # Override nose trying to disable plugin.
         self.enabled = True
         
     def wantFile(self, filename):
         """Return whether the given filename should be scanned for tests.
         """
         if any(pat in filename for pat in self.exclude_patterns):
             return False
         return None
 
     def wantDirectory(self, directory):
         """Return whether the given directory should be scanned for tests.
         """
         if any(pat in directory for pat in self.exclude_patterns):
             return False
         return None
 
 
 class StreamCapturer(Thread):
     daemon = True  # Don't hang if main thread crashes
     started = False
     def __init__(self, echo=False):
         super(StreamCapturer, self).__init__()
         self.echo = echo
         self.streams = []
         self.buffer = BytesIO()
         self.readfd, self.writefd = os.pipe()
         self.buffer_lock = Lock()
         self.stop = Event()
 
     def run(self):
         self.started = True
 
         while not self.stop.is_set():
             chunk = os.read(self.readfd, 1024)
 
             with self.buffer_lock:
                 self.buffer.write(chunk)
             if self.echo:
                 sys.stdout.write(bytes_to_str(chunk))
     
         os.close(self.readfd)
         os.close(self.writefd)
 
     def reset_buffer(self):
         with self.buffer_lock:
             self.buffer.truncate(0)
             self.buffer.seek(0)
 
     def get_buffer(self):
         with self.buffer_lock:
             return self.buffer.getvalue()
 
     def ensure_started(self):
         if not self.started:
             self.start()
 
     def halt(self):
         """Safely stop the thread."""
         if not self.started:
             return
 
         self.stop.set()
         os.write(self.writefd, b'\0')  # Ensure we're not locked in a read()
         self.join()
 
 class SubprocessStreamCapturePlugin(Plugin):
     name='subprocstreams'
     def __init__(self):
         Plugin.__init__(self)
         self.stream_capturer = StreamCapturer()
         self.destination = os.environ.get('IPTEST_SUBPROC_STREAMS', 'capture')
         # This is ugly, but distant parts of the test machinery need to be able
         # to redirect streams, so we make the object globally accessible.
         nose.iptest_stdstreams_fileno = self.get_write_fileno
 
     def get_write_fileno(self):
         if self.destination == 'capture':
             self.stream_capturer.ensure_started()
             return self.stream_capturer.writefd
         elif self.destination == 'discard':
             return os.open(os.devnull, os.O_WRONLY)
         else:
             return sys.__stdout__.fileno()
     
     def configure(self, options, config):
         Plugin.configure(self, options, config)
         # Override nose trying to disable plugin.
         if self.destination == 'capture':
             self.enabled = True
     
     def startTest(self, test):
         # Reset log capture
         self.stream_capturer.reset_buffer()
     
     def formatFailure(self, test, err):
         # Show output
         ec, ev, tb = err
         captured = self.stream_capturer.get_buffer().decode('utf-8', 'replace')
         if captured.strip():
             ev = safe_str(ev)
             out = [ev, '>> begin captured subprocess output <<',
                     captured,
                     '>> end captured subprocess output <<']
             return ec, '\n'.join(out), tb
 
         return err
     
     formatError = formatFailure
     
     def finalize(self, result):
         self.stream_capturer.halt()
 
 
 def run_iptest():
     """Run the IPython test suite using nose.
 
     This function is called when this script is **not** called with the form
     `iptest all`.  It simply calls nose with appropriate command line flags
     and accepts all of the standard nose arguments.
     """
     # Apply our monkeypatch to Xunit
     if '--with-xunit' in sys.argv and not hasattr(Xunit, 'orig_addError'):
         monkeypatch_xunit()
 
     arg1 = sys.argv[1]
     if arg1 in test_sections:
         section = test_sections[arg1]
         sys.argv[1:2] = section.includes
     elif arg1.startswith('IPython.') and arg1[8:] in test_sections:
         section = test_sections[arg1[8:]]
         sys.argv[1:2] = section.includes
     else:
         section = TestSection(arg1, includes=[arg1])
         
 
     argv = sys.argv + [ '--detailed-errors',  # extra info in tracebacks
                         # We add --exe because of setuptools' imbecility (it
                         # blindly does chmod +x on ALL files).  Nose does the
                         # right thing and it tries to avoid executables,
                         # setuptools unfortunately forces our hand here.  This
                         # has been discussed on the distutils list and the
                         # setuptools devs refuse to fix this problem!
                         '--exe',
                         ]
     if '-a' not in argv and '-A' not in argv:
         argv = argv + ['-a', '!crash']
 
     if nose.__version__ >= '0.11':
         # I don't fully understand why we need this one, but depending on what
         # directory the test suite is run from, if we don't give it, 0 tests
         # get run.  Specifically, if the test suite is run from the source dir
         # with an argument (like 'iptest.py IPython.core', 0 tests are run,
         # even if the same call done in this directory works fine).  It appears
         # that if the requested package is in the current dir, nose bails early
         # by default.  Since it's otherwise harmless, leave it in by default
         # for nose >= 0.11, though unfortunately nose 0.10 doesn't support it.
         argv.append('--traverse-namespace')
 
     plugins = [ ExclusionPlugin(section.excludes), KnownFailure(),
                SubprocessStreamCapturePlugin() ]
     
     # we still have some vestigial doctests in core
-    if (section.name.startswith(('core', 'IPython.core'))):
+    if (section.name.startswith(('core', 'IPython.core', 'IPython.utils'))):
         plugins.append(IPythonDoctest())
         argv.extend([
             '--with-ipdoctest',
             '--ipdoctest-tests',
             '--ipdoctest-extension=txt',
         ])
 
     
     # Use working directory set by parent process (see iptestcontroller)
     if 'IPTEST_WORKING_DIR' in os.environ:
         os.chdir(os.environ['IPTEST_WORKING_DIR'])
     
     # We need a global ipython running in this process, but the special
     # in-process group spawns its own IPython kernels, so for *that* group we
     # must avoid also opening the global one (otherwise there's a conflict of
     # singletons).  Ultimately the solution to this problem is to refactor our
     # assumptions about what needs to be a singleton and what doesn't (app
     # objects should, individual shells shouldn't).  But for now, this
     # workaround allows the test suite for the inprocess module to complete.
     if 'kernel.inprocess' not in section.name:
         from IPython.testing import globalipapp
         globalipapp.start_ipython()
 
     # Now nose can run
     TestProgram(argv=argv, addplugins=plugins)
 
 if __name__ == '__main__':
     run_iptest()

IPython/utils/text.py

@@ -1,779 +1,774 b''
 # encoding: utf-8
 """
 Utilities for working with strings and text.
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.utils.text
    :parts: 3
 """
 
 import os
 import re
 import sys
 import textwrap
 from string import Formatter
 try:
     from pathlib import Path
 except ImportError:
     # Python 2 backport
     from pathlib2 import Path
 
 from IPython.utils import py3compat
 
 # datetime.strftime date format for ipython
 if sys.platform == 'win32':
     date_format = "%B %d, %Y"
 else:
     date_format = "%B %-d, %Y"
 
 class LSString(str):
     """String derivative with a special access attributes.
 
     These are normal strings, but with the special attributes:
 
         .l (or .list) : value as list (split on newlines).
         .n (or .nlstr): original value (the string itself).
         .s (or .spstr): value as whitespace-separated string.
         .p (or .paths): list of path objects (requires path.py package)
 
     Any values which require transformations are computed only once and
     cached.
 
     Such strings are very useful to efficiently interact with the shell, which
     typically only understands whitespace-separated options for commands."""
 
     def get_list(self):
         try:
             return self.__list
         except AttributeError:
             self.__list = self.split('\n')
             return self.__list
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = self.replace('\n',' ')
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         return self
 
     n = nlstr = property(get_nlstr)
 
     def get_paths(self):
         try:
             return self.__paths
         except AttributeError:
             self.__paths = [Path(p) for p in self.split('\n') if os.path.exists(p)]
             return self.__paths
 
     p = paths = property(get_paths)
 
 # FIXME: We need to reimplement type specific displayhook and then add this
 # back as a custom printer. This should also be moved outside utils into the
 # core.
 
 # def print_lsstring(arg):
 #     """ Prettier (non-repr-like) and more informative printer for LSString """
 #     print "LSString (.p, .n, .l, .s available). Value:"
 #     print arg
 #
 #
 # print_lsstring = result_display.when_type(LSString)(print_lsstring)
 
 
 class SList(list):
     """List derivative with a special access attributes.
 
     These are normal lists, but with the special attributes:
 
     * .l (or .list) : value as list (the list itself).
     * .n (or .nlstr): value as a string, joined on newlines.
     * .s (or .spstr): value as a string, joined on spaces.
     * .p (or .paths): list of path objects (requires path.py package)
 
     Any values which require transformations are computed only once and
     cached."""
 
     def get_list(self):
         return self
 
     l = list = property(get_list)
 
     def get_spstr(self):
         try:
             return self.__spstr
         except AttributeError:
             self.__spstr = ' '.join(self)
             return self.__spstr
 
     s = spstr = property(get_spstr)
 
     def get_nlstr(self):
         try:
             return self.__nlstr
         except AttributeError:
             self.__nlstr = '\n'.join(self)
             return self.__nlstr
 
     n = nlstr = property(get_nlstr)
 
     def get_paths(self):
         try:
             return self.__paths
         except AttributeError:
             self.__paths = [Path(p) for p in self if os.path.exists(p)]
             return self.__paths
 
     p = paths = property(get_paths)
 
     def grep(self, pattern, prune = False, field = None):
         """ Return all strings matching 'pattern' (a regex or callable)
 
         This is case-insensitive. If prune is true, return all items
         NOT matching the pattern.
 
         If field is specified, the match must occur in the specified
         whitespace-separated field.
 
         Examples::
 
             a.grep( lambda x: x.startswith('C') )
             a.grep('Cha.*log', prune=1)
             a.grep('chm', field=-1)
         """
 
         def match_target(s):
             if field is None:
                 return s
             parts = s.split()
             try:
                 tgt = parts[field]
                 return tgt
             except IndexError:
                 return ""
 
         if isinstance(pattern, py3compat.string_types):
             pred = lambda x : re.search(pattern, x, re.IGNORECASE)
         else:
             pred = pattern
         if not prune:
             return SList([el for el in self if pred(match_target(el))])
         else:
             return SList([el for el in self if not pred(match_target(el))])
 
     def fields(self, *fields):
         """ Collect whitespace-separated fields from string list
 
         Allows quick awk-like usage of string lists.
 
         Example data (in var a, created by 'a = !ls -l')::
 
             -rwxrwxrwx  1 ville None      18 Dec 14  2006 ChangeLog
             drwxrwxrwx+ 6 ville None       0 Oct 24 18:05 IPython
 
         * ``a.fields(0)`` is ``['-rwxrwxrwx', 'drwxrwxrwx+']``
         * ``a.fields(1,0)`` is ``['1 -rwxrwxrwx', '6 drwxrwxrwx+']``
           (note the joining by space).
         * ``a.fields(-1)`` is ``['ChangeLog', 'IPython']``
 
         IndexErrors are ignored.
 
         Without args, fields() just split()'s the strings.
         """
         if len(fields) == 0:
             return [el.split() for el in self]
 
         res = SList()
         for el in [f.split() for f in self]:
             lineparts = []
 
             for fd in fields:
                 try:
                     lineparts.append(el[fd])
                 except IndexError:
                     pass
             if lineparts:
                 res.append(" ".join(lineparts))
 
         return res
 
     def sort(self,field= None,  nums = False):
         """ sort by specified fields (see fields())
 
         Example::
 
             a.sort(1, nums = True)
 
         Sorts a by second field, in numerical order (so that 21 > 3)
 
         """
 
         #decorate, sort, undecorate
         if field is not None:
             dsu = [[SList([line]).fields(field),  line] for line in self]
         else:
             dsu = [[line,  line] for line in self]
         if nums:
             for i in range(len(dsu)):
                 numstr = "".join([ch for ch in dsu[i][0] if ch.isdigit()])
                 try:
                     n = int(numstr)
                 except ValueError:
                     n = 0
                 dsu[i][0] = n
 
 
         dsu.sort()
         return SList([t[1] for t in dsu])
 
 
 # FIXME: We need to reimplement type specific displayhook and then add this
 # back as a custom printer. This should also be moved outside utils into the
 # core.
 
 # def print_slist(arg):
 #     """ Prettier (non-repr-like) and more informative printer for SList """
 #     print "SList (.p, .n, .l, .s, .grep(), .fields(), sort() available):"
 #     if hasattr(arg,  'hideonce') and arg.hideonce:
 #         arg.hideonce = False
 #         return
 #
 #     nlprint(arg)   # This was a nested list printer, now removed.
 #
 # print_slist = result_display.when_type(SList)(print_slist)
 
 
 def indent(instr,nspaces=4, ntabs=0, flatten=False):
     """Indent a string a given number of spaces or tabstops.
 
     indent(str,nspaces=4,ntabs=0) -> indent str by ntabs+nspaces.
 
     Parameters
     ----------
 
     instr : basestring
         The string to be indented.
     nspaces : int (default: 4)
         The number of spaces to be indented.
     ntabs : int (default: 0)
         The number of tabs to be indented.
     flatten : bool (default: False)
         Whether to scrub existing indentation.  If True, all lines will be
         aligned to the same indentation.  If False, existing indentation will
         be strictly increased.
 
     Returns
     -------
 
     str|unicode : string indented by ntabs and nspaces.
 
     """
     if instr is None:
         return
     ind = '\t'*ntabs+' '*nspaces
     if flatten:
         pat = re.compile(r'^\s*', re.MULTILINE)
     else:
         pat = re.compile(r'^', re.MULTILINE)
     outstr = re.sub(pat, ind, instr)
     if outstr.endswith(os.linesep+ind):
         return outstr[:-len(ind)]
     else:
         return outstr
 
 
 def list_strings(arg):
     """Always return a list of strings, given a string or list of strings
     as input.
 
     Examples
     --------
     ::
 
         In [7]: list_strings('A single string')
         Out[7]: ['A single string']
 
         In [8]: list_strings(['A single string in a list'])
         Out[8]: ['A single string in a list']
 
         In [9]: list_strings(['A','list','of','strings'])
         Out[9]: ['A', 'list', 'of', 'strings']
     """
 
     if isinstance(arg, py3compat.string_types): return [arg]
     else: return arg
 
 
 def marquee(txt='',width=78,mark='*'):
     """Return the input string centered in a 'marquee'.
 
     Examples
     --------
     ::
 
         In [16]: marquee('A test',40)
         Out[16]: '**************** A test ****************'
 
         In [17]: marquee('A test',40,'-')
         Out[17]: '---------------- A test ----------------'
 
         In [18]: marquee('A test',40,' ')
         Out[18]: '                 A test                 '
 
     """
     if not txt:
         return (mark*width)[:width]
     nmark = (width-len(txt)-2)//len(mark)//2
     if nmark < 0: nmark =0
     marks = mark*nmark
     return '%s %s %s' % (marks,txt,marks)
 
 
 ini_spaces_re = re.compile(r'^(\s+)')
 
 def num_ini_spaces(strng):
     """Return the number of initial spaces in a string"""
 
     ini_spaces = ini_spaces_re.match(strng)
     if ini_spaces:
         return ini_spaces.end()
     else:
         return 0
 
 
 def format_screen(strng):
     """Format a string for screen printing.
 
     This removes some latex-type format codes."""
     # Paragraph continue
     par_re = re.compile(r'\\$',re.MULTILINE)
     strng = par_re.sub('',strng)
     return strng
 
 
 def dedent(text):
     """Equivalent of textwrap.dedent that ignores unindented first line.
 
     This means it will still dedent strings like:
     '''foo
     is a bar
     '''
 
     For use in wrap_paragraphs.
     """
 
     if text.startswith('\n'):
         # text starts with blank line, don't ignore the first line
         return textwrap.dedent(text)
 
     # split first line
     splits = text.split('\n',1)
     if len(splits) == 1:
         # only one line
         return textwrap.dedent(text)
 
     first, rest = splits
     # dedent everything but the first line
     rest = textwrap.dedent(rest)
     return '\n'.join([first, rest])
 
 
 def wrap_paragraphs(text, ncols=80):
     """Wrap multiple paragraphs to fit a specified width.
 
     This is equivalent to textwrap.wrap, but with support for multiple
     paragraphs, as separated by empty lines.
 
     Returns
     -------
 
     list of complete paragraphs, wrapped to fill `ncols` columns.
     """
     paragraph_re = re.compile(r'\n(\s*\n)+', re.MULTILINE)
     text = dedent(text).strip()
     paragraphs = paragraph_re.split(text)[::2] # every other entry is space
     out_ps = []
     indent_re = re.compile(r'\n\s+', re.MULTILINE)
     for p in paragraphs:
         # presume indentation that survives dedent is meaningful formatting,
         # so don't fill unless text is flush.
         if indent_re.search(p) is None:
             # wrap paragraph
             p = textwrap.fill(p, ncols)
         out_ps.append(p)
     return out_ps
 
 
 def long_substr(data):
     """Return the longest common substring in a list of strings.
     
     Credit: http://stackoverflow.com/questions/2892931/longest-common-substring-from-more-than-two-strings-python
     """
     substr = ''
     if len(data) > 1 and len(data[0]) > 0:
         for i in range(len(data[0])):
             for j in range(len(data[0])-i+1):
                 if j > len(substr) and all(data[0][i:i+j] in x for x in data):
                     substr = data[0][i:i+j]
     elif len(data) == 1:
         substr = data[0]
     return substr
 
 
 def strip_email_quotes(text):
     """Strip leading email quotation characters ('>').
 
     Removes any combination of leading '>' interspersed with whitespace that
     appears *identically* in all lines of the input text.
 
     Parameters
     ----------
     text : str
 
     Examples
     --------
 
     Simple uses::
 
         In [2]: strip_email_quotes('> > text')
         Out[2]: 'text'
 
         In [3]: strip_email_quotes('> > text\\n> > more')
         Out[3]: 'text\\nmore'
 
     Note how only the common prefix that appears in all lines is stripped::
 
         In [4]: strip_email_quotes('> > text\\n> > more\\n> more...')
         Out[4]: '> text\\n> more\\nmore...'
 
     So if any line has no quote marks ('>') , then none are stripped from any
     of them ::
     
         In [5]: strip_email_quotes('> > text\\n> > more\\nlast different')
         Out[5]: '> > text\\n> > more\\nlast different'
     """
     lines = text.splitlines()
     matches = set()
     for line in lines:
         prefix = re.match(r'^(\s*>[ >]*)', line)
         if prefix:
             matches.add(prefix.group(1))
         else:
             break
     else:
         prefix = long_substr(list(matches))
         if prefix:
             strip = len(prefix)
             text = '\n'.join([ ln[strip:] for ln in lines])
     return text
 
 def strip_ansi(source):
     """
     Remove ansi escape codes from text.
     
     Parameters
     ----------
     source : str
         Source to remove the ansi from
     """
     return re.sub(r'\033\[(\d|;)+?m', '', source)
 
 
 class EvalFormatter(Formatter):
     """A String Formatter that allows evaluation of simple expressions.
     
     Note that this version interprets a : as specifying a format string (as per
     standard string formatting), so if slicing is required, you must explicitly
     create a slice.
     
     This is to be used in templating cases, such as the parallel batch
     script templates, where simple arithmetic on arguments is useful.
 
     Examples
     --------
     ::
 
         In [1]: f = EvalFormatter()
         In [2]: f.format('{n//4}', n=8)
         Out[2]: '2'
 
         In [3]: f.format("{greeting[slice(2,4)]}", greeting="Hello")
         Out[3]: 'll'
     """
     def get_field(self, name, args, kwargs):
         v = eval(name, kwargs)
         return v, name
 
 #XXX: As of Python 3.4, the format string parsing no longer splits on a colon
 # inside [], so EvalFormatter can handle slicing. Once we only support 3.4 and
 # above, it should be possible to remove FullEvalFormatter.
 
 class FullEvalFormatter(Formatter):
     """A String Formatter that allows evaluation of simple expressions.
     
     Any time a format key is not found in the kwargs,
     it will be tried as an expression in the kwargs namespace.
     
     Note that this version allows slicing using [1:2], so you cannot specify
     a format string. Use :class:`EvalFormatter` to permit format strings.
     
     Examples
     --------
     ::
 
         In [1]: f = FullEvalFormatter()
         In [2]: f.format('{n//4}', n=8)
         Out[2]: '2'
 
         In [3]: f.format('{list(range(5))[2:4]}')
         Out[3]: '[2, 3]'
 
         In [4]: f.format('{3*2}')
         Out[4]: '6'
     """
     # copied from Formatter._vformat with minor changes to allow eval
     # and replace the format_spec code with slicing
     def vformat(self, format_string, args, kwargs):
         result = []
         for literal_text, field_name, format_spec, conversion in \
                 self.parse(format_string):
 
             # output the literal text
             if literal_text:
                 result.append(literal_text)
 
             # if there's a field, output it
             if field_name is not None:
                 # this is some markup, find the object and do
                 # the formatting
 
                 if format_spec:
                     # override format spec, to allow slicing:
                     field_name = ':'.join([field_name, format_spec])
 
                 # eval the contents of the field for the object
                 # to be formatted
                 obj = eval(field_name, kwargs)
 
                 # do any conversion on the resulting object
                 obj = self.convert_field(obj, conversion)
 
                 # format the object and append to the result
                 result.append(self.format_field(obj, ''))
 
         return u''.join(py3compat.cast_unicode(s) for s in result)
 
 
 class DollarFormatter(FullEvalFormatter):
     """Formatter allowing Itpl style $foo replacement, for names and attribute
     access only. Standard {foo} replacement also works, and allows full
     evaluation of its arguments.
 
     Examples
     --------
     ::
 
         In [1]: f = DollarFormatter()
         In [2]: f.format('{n//4}', n=8)
         Out[2]: '2'
 
         In [3]: f.format('23 * 76 is $result', result=23*76)
         Out[3]: '23 * 76 is 1748'
 
         In [4]: f.format('$a or {b}', a=1, b=2)
         Out[4]: '1 or 2'
     """
     _dollar_pattern = re.compile("(.*?)\$(\$?[\w\.]+)")
     def parse(self, fmt_string):
         for literal_txt, field_name, format_spec, conversion \
                     in Formatter.parse(self, fmt_string):
             
             # Find $foo patterns in the literal text.
             continue_from = 0
             txt = ""
             for m in self._dollar_pattern.finditer(literal_txt):
                 new_txt, new_field = m.group(1,2)
                 # $$foo --> $foo
                 if new_field.startswith("$"):
                     txt += new_txt + new_field
                 else:
                     yield (txt + new_txt, new_field, "", None)
                     txt = ""
                 continue_from = m.end()
             
             # Re-yield the {foo} style pattern
             yield (txt + literal_txt[continue_from:], field_name, format_spec, conversion)
 
 #-----------------------------------------------------------------------------
 # Utils to columnize a list of string
 #-----------------------------------------------------------------------------
 
 def _col_chunks(l, max_rows, row_first=False):
     """Yield successive max_rows-sized column chunks from l."""
     if row_first:
         ncols = (len(l) // max_rows) + (len(l) % max_rows > 0)
         for i in py3compat.xrange(ncols):
             yield [l[j] for j in py3compat.xrange(i, len(l), ncols)]
     else:
         for i in py3compat.xrange(0, len(l), max_rows):
             yield l[i:(i + max_rows)]
 
 
 def _find_optimal(rlist, row_first=False, separator_size=2, displaywidth=80):
     """Calculate optimal info to columnize a list of string"""
     for max_rows in range(1, len(rlist) + 1):
         col_widths = list(map(max, _col_chunks(rlist, max_rows, row_first)))
         sumlength = sum(col_widths)
         ncols = len(col_widths)
         if sumlength + separator_size * (ncols - 1) <= displaywidth:
             break
     return {'num_columns': ncols,
-            'optimal_separator_width': (displaywidth - sumlength) / (ncols - 1) if (ncols - 1) else 0,
+            'optimal_separator_width': (displaywidth - sumlength) // (ncols - 1) if (ncols - 1) else 0,
             'max_rows': max_rows,
             'column_widths': col_widths
             }
 
 
 def _get_or_default(mylist, i, default=None):
     """return list item number, or default if don't exist"""
     if i >= len(mylist):
         return default
     else :
         return mylist[i]
 
 
 def compute_item_matrix(items, row_first=False, empty=None, *args, **kwargs) :
     """Returns a nested list, and info to columnize items
 
     Parameters
     ----------
 
     items
         list of strings to columize
     row_first : (default False)
         Whether to compute columns for a row-first matrix instead of
         column-first (default).
     empty : (default None)
         default value to fill list if needed
     separator_size : int (default=2)
         How much caracters will be used as a separation between each columns.
     displaywidth : int (default=80)
         The width of the area onto wich the columns should enter
 
     Returns
     -------
 
     strings_matrix
 
         nested list of string, the outer most list contains as many list as
         rows, the innermost lists have each as many element as colums. If the
         total number of elements in `items` does not equal the product of
         rows*columns, the last element of some lists are filled with `None`.
 
     dict_info
         some info to make columnize easier:
 
         num_columns
           number of columns
         max_rows
           maximum number of rows (final number may be less)
         column_widths
           list of with of each columns
         optimal_separator_width
           best separator width between columns
 
     Examples
     --------
     ::
 
         In [1]: l = ['aaa','b','cc','d','eeeee','f','g','h','i','j','k','l']
-           ...: compute_item_matrix(l, displaywidth=12)
-        Out[1]:
-            ([['aaa', 'f', 'k'],
-            ['b', 'g', 'l'],
-            ['cc', 'h', None],
-            ['d', 'i', None],
-            ['eeeee', 'j', None]],
-            {'num_columns': 3,
-            'column_widths': [5, 1, 1],
-            'optimal_separator_width': 2,
-            'max_rows': 5})
+        In [2]: list, info = compute_item_matrix(l, displaywidth=12)
+        In [3]: list
+        Out[3]: [['aaa', 'f', 'k'], ['b', 'g', 'l'], ['cc', 'h', None], ['d', 'i', None], ['eeeee', 'j', None]]
+        In [4]: ideal = {'num_columns': 3, 'column_widths': [5, 1, 1], 'optimal_separator_width': 2, 'max_rows': 5}
+        In [5]: all((info[k] == ideal[k] for k in ideal.keys()))
+        Out[5]: True
     """
     info = _find_optimal(list(map(len, items)), row_first, *args, **kwargs)
     nrow, ncol = info['max_rows'], info['num_columns']
     if row_first:
         return ([[_get_or_default(items, r * ncol + c, default=empty) for c in range(ncol)] for r in range(nrow)], info)
     else:
         return ([[_get_or_default(items, c * nrow + r, default=empty) for c in range(ncol)] for r in range(nrow)], info)
 
 
 def columnize(items, row_first=False, separator='  ', displaywidth=80, spread=False):
     """ Transform a list of strings into a single string with columns.
 
     Parameters
     ----------
     items : sequence of strings
         The strings to process.
 
     row_first : (default False)
         Whether to compute columns for a row-first matrix instead of
         column-first (default).
 
     separator : str, optional [default is two spaces]
         The string that separates columns.
 
     displaywidth : int, optional [default is 80]
         Width of the display in number of characters.
 
     Returns
     -------
     The formatted string.
     """
     if not items:
         return '\n'
     matrix, info = compute_item_matrix(items, row_first=row_first, separator_size=len(separator), displaywidth=displaywidth)
     if spread:
         separator = separator.ljust(int(info['optimal_separator_width']))
     fmatrix = [filter(None, x) for x in matrix]
     sjoin = lambda x : separator.join([ y.ljust(w, ' ') for y, w in zip(x, info['column_widths'])])
     return '\n'.join(map(sjoin, fmatrix))+'\n'
 
 
 def get_text_list(list_, last_sep=' and ', sep=", ", wrap_item_with=""):
     """
     Return a string with a natural enumeration of items
 
     >>> get_text_list(['a', 'b', 'c', 'd'])
     'a, b, c and d'
     >>> get_text_list(['a', 'b', 'c'], ' or ')
     'a, b or c'
     >>> get_text_list(['a', 'b', 'c'], ', ')
     'a, b, c'
     >>> get_text_list(['a', 'b'], ' or ')
     'a or b'
     >>> get_text_list(['a'])
     'a'
     >>> get_text_list([])
     ''
     >>> get_text_list(['a', 'b'], wrap_item_with="`")
     '`a` and `b`'
     >>> get_text_list(['a', 'b', 'c', 'd'], " = ", sep=" + ")
     'a + b + c = d'
     """
     if len(list_) == 0:
         return ''
     if wrap_item_with:
         list_ = ['%s%s%s' % (wrap_item_with, item, wrap_item_with) for
                  item in list_]
     if len(list_) == 1:
         return list_[0]
     return '%s%s%s' % (
         sep.join(i for i in list_[:-1]),
         last_sep, list_[-1])