Don't fail when completing modules ending with dot.

Mitigate  #10170 don't considered as a fix as it does not populate the
completion, just prevent crash.

IPython/core/completerlib.py

@@ -1,347 +1,352 b''
 # encoding: utf-8
 """Implementations for various useful completers.
 
 These are all loaded by default by IPython.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010-2011 The IPython Development Team.
 #
 #  Distributed under the terms of the BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib imports
 import glob
 import inspect
 import os
 import re
 import sys
 from importlib import import_module
 from importlib.machinery import all_suffixes
 
 
 # Third-party imports
 from time import time
 from zipimport import zipimporter
 
 # Our own imports
 from IPython.core.completer import expand_user, compress_user
 from IPython.core.error import TryNext
 from IPython.utils._process_common import arg_split
 
 # FIXME: this should be pulled in with the right call via the component system
 from IPython import get_ipython
 
 #-----------------------------------------------------------------------------
 # Globals and constants
 #-----------------------------------------------------------------------------
 _suffixes = all_suffixes()
 
 # Time in seconds after which the rootmodules will be stored permanently in the
 # ipython ip.db database (kept in the user's .ipython dir).
 TIMEOUT_STORAGE = 2
 
 # Time in seconds after which we give up
 TIMEOUT_GIVEUP = 20
 
 # Regular expression for the python import statement
 import_re = re.compile(r'(?P<name>[a-zA-Z_][a-zA-Z0-9_]*?)'
                        r'(?P<package>[/\\]__init__)?'
                        r'(?P<suffix>%s)$' %
                        r'|'.join(re.escape(s) for s in _suffixes))
 
 # RE for the ipython %run command (python + ipython scripts)
 magic_run_re = re.compile(r'.*(\.ipy|\.ipynb|\.py[w]?)$')
 
 #-----------------------------------------------------------------------------
 # Local utilities
 #-----------------------------------------------------------------------------
 
 def module_list(path):
     """
     Return the list containing the names of the modules available in the given
     folder.
     """
     # sys.path has the cwd as an empty string, but isdir/listdir need it as '.'
     if path == '':
         path = '.'
 
     # A few local constants to be used in loops below
     pjoin = os.path.join
 
     if os.path.isdir(path):
         # Build a list of all files in the directory and all files
         # in its subdirectories. For performance reasons, do not
         # recurse more than one level into subdirectories.
         files = []
         for root, dirs, nondirs in os.walk(path, followlinks=True):
             subdir = root[len(path)+1:]
             if subdir:
                 files.extend(pjoin(subdir, f) for f in nondirs)
                 dirs[:] = [] # Do not recurse into additional subdirectories.
             else:
                 files.extend(nondirs)
 
     else:
         try:
             files = list(zipimporter(path)._files.keys())
         except:
             files = []
 
     # Build a list of modules which match the import_re regex.
     modules = []
     for f in files:
         m = import_re.match(f)
         if m:
             modules.append(m.group('name'))
     return list(set(modules))
 
 
 def get_root_modules():
     """
     Returns a list containing the names of all the modules available in the
     folders of the pythonpath.
 
     ip.db['rootmodules_cache'] maps sys.path entries to list of modules.
     """
     ip = get_ipython()
     if ip is None:
         # No global shell instance to store cached list of modules.
         # Don't try to scan for modules every time.
         return list(sys.builtin_module_names)
 
     rootmodules_cache = ip.db.get('rootmodules_cache', {})
     rootmodules = list(sys.builtin_module_names)
     start_time = time()
     store = False
     for path in sys.path:
         try:
             modules = rootmodules_cache[path]
         except KeyError:
             modules = module_list(path)
             try:
                 modules.remove('__init__')
             except ValueError:
                 pass
             if path not in ('', '.'): # cwd modules should not be cached
                 rootmodules_cache[path] = modules
             if time() - start_time > TIMEOUT_STORAGE and not store:
                 store = True
                 print("\nCaching the list of root modules, please wait!")
                 print("(This will only be done once - type '%rehashx' to "
                       "reset cache!)\n")
                 sys.stdout.flush()
             if time() - start_time > TIMEOUT_GIVEUP:
                 print("This is taking too long, we give up.\n")
                 return []
         rootmodules.extend(modules)
     if store:
         ip.db['rootmodules_cache'] = rootmodules_cache
     rootmodules = list(set(rootmodules))
     return rootmodules
 
 
 def is_importable(module, attr, only_modules):
     if only_modules:
         return inspect.ismodule(getattr(module, attr))
     else:
         return not(attr[:2] == '__' and attr[-2:] == '__')
 
-def try_import(mod, only_modules=False):
+
+def try_import(mod: str, only_modules=False):
+    """
+    Try to import given module and return list of potential completions.
+    """
+    mod = mod.rstrip('.')
     try:
         m = import_module(mod)
     except:
         return []
 
     m_is_init = hasattr(m, '__file__') and '__init__' in m.__file__
 
     completions = []
     if (not hasattr(m, '__file__')) or (not only_modules) or m_is_init:
         completions.extend( [attr for attr in dir(m) if
                              is_importable(m, attr, only_modules)])
 
     completions.extend(getattr(m, '__all__', []))
     if m_is_init:
         completions.extend(module_list(os.path.dirname(m.__file__)))
     completions = {c for c in completions if isinstance(c, str)}
     completions.discard('__init__')
     return list(completions)
 
 
 #-----------------------------------------------------------------------------
 # Completion-related functions.
 #-----------------------------------------------------------------------------
 
 def quick_completer(cmd, completions):
     """ Easily create a trivial completer for a command.
 
     Takes either a list of completions, or all completions in string (that will
     be split on whitespace).
 
     Example::
 
         [d:\ipython]|1> import ipy_completers
         [d:\ipython]|2> ipy_completers.quick_completer('foo', ['bar','baz'])
         [d:\ipython]|3> foo b<TAB>
         bar baz
         [d:\ipython]|3> foo ba
     """
 
     if isinstance(completions, str):
         completions = completions.split()
 
     def do_complete(self, event):
         return completions
 
     get_ipython().set_hook('complete_command',do_complete, str_key = cmd)
 
 def module_completion(line):
     """
     Returns a list containing the completion possibilities for an import line.
 
     The line looks like this :
     'import xml.d'
     'from xml.dom import'
     """
 
     words = line.split(' ')
     nwords = len(words)
 
     # from whatever <tab> -> 'import '
     if nwords == 3 and words[0] == 'from':
         return ['import ']
 
     # 'from xy<tab>' or 'import xy<tab>'
     if nwords < 3 and (words[0] in {'%aimport', 'import', 'from'}) :
         if nwords == 1:
             return get_root_modules()
         mod = words[1].split('.')
         if len(mod) < 2:
             return get_root_modules()
         completion_list = try_import('.'.join(mod[:-1]), True)
         return ['.'.join(mod[:-1] + [el]) for el in completion_list]
 
     # 'from xyz import abc<tab>'
     if nwords >= 3 and words[0] == 'from':
         mod = words[1]
         return try_import(mod)
 
 #-----------------------------------------------------------------------------
 # Completers
 #-----------------------------------------------------------------------------
 # These all have the func(self, event) signature to be used as custom
 # completers
 
 def module_completer(self,event):
     """Give completions after user has typed 'import ...' or 'from ...'"""
 
     # This works in all versions of python.  While 2.5 has
     # pkgutil.walk_packages(), that particular routine is fairly dangerous,
     # since it imports *EVERYTHING* on sys.path.  That is: a) very slow b) full
     # of possibly problematic side effects.
     # This search the folders in the sys.path for available modules.
 
     return module_completion(event.line)
 
 # FIXME: there's a lot of logic common to the run, cd and builtin file
 # completers, that is currently reimplemented in each.
 
 def magic_run_completer(self, event):
     """Complete files that end in .py or .ipy or .ipynb for the %run command.
     """
     comps = arg_split(event.line, strict=False)
     # relpath should be the current token that we need to complete.
     if (len(comps) > 1) and (not event.line.endswith(' ')):
         relpath = comps[-1].strip("'\"")
     else:
         relpath = ''
 
     #print("\nev=", event)  # dbg
     #print("rp=", relpath)  # dbg
     #print('comps=', comps)  # dbg
 
     lglob = glob.glob
     isdir = os.path.isdir
     relpath, tilde_expand, tilde_val = expand_user(relpath)
 
     # Find if the user has already typed the first filename, after which we
     # should complete on all files, since after the first one other files may
     # be arguments to the input script.
 
     if any(magic_run_re.match(c) for c in comps):
         matches =  [f.replace('\\','/') + ('/' if isdir(f) else '')
                             for f in lglob(relpath+'*')]
     else:
         dirs = [f.replace('\\','/') + "/" for f in lglob(relpath+'*') if isdir(f)]
         pys =  [f.replace('\\','/')
                 for f in lglob(relpath+'*.py') + lglob(relpath+'*.ipy') +
                 lglob(relpath+'*.ipynb') + lglob(relpath + '*.pyw')]
 
         matches = dirs + pys
 
     #print('run comp:', dirs+pys) # dbg
     return [compress_user(p, tilde_expand, tilde_val) for p in matches]
 
 
 def cd_completer(self, event):
     """Completer function for cd, which only returns directories."""
     ip = get_ipython()
     relpath = event.symbol
 
     #print(event) # dbg
     if event.line.endswith('-b') or ' -b ' in event.line:
         # return only bookmark completions
         bkms = self.db.get('bookmarks', None)
         if bkms:
             return bkms.keys()
         else:
             return []
 
     if event.symbol == '-':
         width_dh = str(len(str(len(ip.user_ns['_dh']) + 1)))
         # jump in directory history by number
         fmt = '-%0' + width_dh +'d [%s]'
         ents = [ fmt % (i,s) for i,s in enumerate(ip.user_ns['_dh'])]
         if len(ents) > 1:
             return ents
         return []
 
     if event.symbol.startswith('--'):
         return ["--" + os.path.basename(d) for d in ip.user_ns['_dh']]
 
     # Expand ~ in path and normalize directory separators.
     relpath, tilde_expand, tilde_val = expand_user(relpath)
     relpath = relpath.replace('\\','/')
 
     found = []
     for d in [f.replace('\\','/') + '/' for f in glob.glob(relpath+'*')
               if os.path.isdir(f)]:
         if ' ' in d:
             # we don't want to deal with any of that, complex code
             # for this is elsewhere
             raise TryNext
 
         found.append(d)
 
     if not found:
         if os.path.isdir(relpath):
             return [compress_user(relpath, tilde_expand, tilde_val)]
 
         # if no completions so far, try bookmarks
         bks = self.db.get('bookmarks',{})
         bkmatches = [s for s in bks if s.startswith(event.symbol)]
         if bkmatches:
             return bkmatches
 
         raise TryNext
 
     return [compress_user(p, tilde_expand, tilde_val) for p in found]
 
 def reset_completer(self, event):
     "A completer for %reset magic"
     return '-f -s in out array dhist'.split()

IPython/core/tests/test_completer.py

@@ -1,738 +1,746 b''
 # encoding: utf-8
 """Tests for the IPython tab-completion machinery."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 import sys
 import unittest
 
 from contextlib import contextmanager
 
 import nose.tools as nt
 
 from traitlets.config.loader import Config
 from IPython import get_ipython
 from IPython.core import completer
 from IPython.external.decorators import knownfailureif
 from IPython.utils.tempdir import TemporaryDirectory, TemporaryWorkingDirectory
 from IPython.utils.generics import complete_object
 from IPython.testing import decorators as dec
 
 #-----------------------------------------------------------------------------
 # Test functions
 #-----------------------------------------------------------------------------
 
 @contextmanager
 def greedy_completion():
     ip = get_ipython()
     greedy_original = ip.Completer.greedy
     try:
         ip.Completer.greedy = True
         yield
     finally:
         ip.Completer.greedy = greedy_original
 
 def test_protect_filename():
     if sys.platform == 'win32':
         pairs = [('abc','abc'),
                  (' abc','" abc"'),
                  ('a bc','"a bc"'),
                  ('a  bc','"a  bc"'),
                  ('  bc','"  bc"'),
                  ]
     else:
         pairs = [('abc','abc'),
                  (' abc',r'\ abc'),
                  ('a bc',r'a\ bc'),
                  ('a  bc',r'a\ \ bc'),
                  ('  bc',r'\ \ bc'),
                  # On posix, we also protect parens and other special characters.
                  ('a(bc',r'a\(bc'),
                  ('a)bc',r'a\)bc'),
                  ('a( )bc',r'a\(\ \)bc'),
                  ('a[1]bc', r'a\[1\]bc'),
                  ('a{1}bc', r'a\{1\}bc'),
                  ('a#bc', r'a\#bc'),
                  ('a?bc', r'a\?bc'),
                  ('a=bc', r'a\=bc'),
                  ('a\\bc', r'a\\bc'),
                  ('a|bc', r'a\|bc'),
                  ('a;bc', r'a\;bc'),
                  ('a:bc', r'a\:bc'),
                  ("a'bc", r"a\'bc"),
                  ('a*bc', r'a\*bc'),
                  ('a"bc', r'a\"bc'),
                  ('a^bc', r'a\^bc'),
                  ('a&bc', r'a\&bc'),
                  ]
     # run the actual tests
     for s1, s2 in pairs:
         s1p = completer.protect_filename(s1)
         nt.assert_equal(s1p, s2)
 
 
 def check_line_split(splitter, test_specs):
     for part1, part2, split in test_specs:
         cursor_pos = len(part1)
         line = part1+part2
         out = splitter.split_line(line, cursor_pos)
         nt.assert_equal(out, split)
 
 
 def test_line_split():
     """Basic line splitter test with default specs."""
     sp = completer.CompletionSplitter()
     # The format of the test specs is: part1, part2, expected answer.  Parts 1
     # and 2 are joined into the 'line' sent to the splitter, as if the cursor
     # was at the end of part1.  So an empty part2 represents someone hitting
     # tab at the end of the line, the most common case.
     t = [('run some/scrip', '', 'some/scrip'),
          ('run scripts/er', 'ror.py foo', 'scripts/er'),
          ('echo $HOM', '', 'HOM'),
          ('print sys.pa', '', 'sys.pa'),
          ('print(sys.pa', '', 'sys.pa'),
          ("execfile('scripts/er", '', 'scripts/er'),
          ('a[x.', '', 'x.'),
          ('a[x.', 'y', 'x.'),
          ('cd "some_file/', '', 'some_file/'),
          ]
     check_line_split(sp, t)
     # Ensure splitting works OK with unicode by re-running the tests with
     # all inputs turned into unicode
     check_line_split(sp, [ map(str, p) for p in t] )
 
 
 def test_custom_completion_error():
     """Test that errors from custom attribute completers are silenced."""
     ip = get_ipython()
     class A(object): pass
     ip.user_ns['a'] = A()
     
     @complete_object.when_type(A)
     def complete_A(a, existing_completions):
         raise TypeError("this should be silenced")
     
     ip.complete("a.")
 
 
 def test_unicode_completions():
     ip = get_ipython()
     # Some strings that trigger different types of completion.  Check them both
     # in str and unicode forms
     s = ['ru', '%ru', 'cd /', 'floa', 'float(x)/']
     for t in s + list(map(str, s)):
         # We don't need to check exact completion values (they may change
         # depending on the state of the namespace, but at least no exceptions
         # should be thrown and the return value should be a pair of text, list
         # values.
         text, matches = ip.complete(t)
         nt.assert_true(isinstance(text, str))
         nt.assert_true(isinstance(matches, list))
 
 def test_latex_completions():
     from IPython.core.latex_symbols import latex_symbols
     import random
     ip = get_ipython()
     # Test some random unicode symbols
     keys = random.sample(latex_symbols.keys(), 10)
     for k in keys:
         text, matches = ip.complete(k)
         nt.assert_equal(len(matches),1)
         nt.assert_equal(text, k)
         nt.assert_equal(matches[0], latex_symbols[k])
     # Test a more complex line
     text, matches = ip.complete(u'print(\\alpha')
     nt.assert_equal(text, u'\\alpha')
     nt.assert_equal(matches[0], latex_symbols['\\alpha'])
     # Test multiple matching latex symbols
     text, matches = ip.complete(u'\\al')
     nt.assert_in('\\alpha', matches)
     nt.assert_in('\\aleph', matches)
 
 
 
 
 def test_back_latex_completion():
     ip = get_ipython()
 
     # do not return more than 1 matches fro \beta, only the latex one.
     name, matches = ip.complete('\\β')
     nt.assert_equal(len(matches), 1)
     nt.assert_equal(matches[0], '\\beta')
 
 def test_back_unicode_completion():
     ip = get_ipython()
     
     name, matches = ip.complete('\\Ⅴ')
     nt.assert_equal(len(matches), 1)
     nt.assert_equal(matches[0], '\\ROMAN NUMERAL FIVE')
 
 
 def test_forward_unicode_completion():
     ip = get_ipython()
     
     name, matches = ip.complete('\\ROMAN NUMERAL FIVE')
     nt.assert_equal(len(matches), 1)
     nt.assert_equal(matches[0], 'Ⅴ')
 
 @dec.knownfailureif(sys.platform == 'win32', 'Fails if there is a C:\\j... path')
 def test_no_ascii_back_completion():
     ip = get_ipython()
     with TemporaryWorkingDirectory():  # Avoid any filename completions
         # single ascii letter that don't have yet completions
         for letter in 'jJ' :
             name, matches = ip.complete('\\'+letter)
             nt.assert_equal(matches, [])
 
 
 
 
 class CompletionSplitterTestCase(unittest.TestCase):
     def setUp(self):
         self.sp = completer.CompletionSplitter()
 
     def test_delim_setting(self):
         self.sp.delims = ' '
         nt.assert_equal(self.sp.delims, ' ')
         nt.assert_equal(self.sp._delim_expr, '[\ ]')
 
     def test_spaces(self):
         """Test with only spaces as split chars."""
         self.sp.delims = ' '
         t = [('foo', '', 'foo'),
              ('run foo', '', 'foo'),
              ('run foo', 'bar', 'foo'),
              ]
         check_line_split(self.sp, t)
 
 
 def test_has_open_quotes1():
     for s in ["'", "'''", "'hi' '"]:
         nt.assert_equal(completer.has_open_quotes(s), "'")
 
 
 def test_has_open_quotes2():
     for s in ['"', '"""', '"hi" "']:
         nt.assert_equal(completer.has_open_quotes(s), '"')
 
 
 def test_has_open_quotes3():
     for s in ["''", "''' '''", "'hi' 'ipython'"]:
         nt.assert_false(completer.has_open_quotes(s))
 
 
 def test_has_open_quotes4():
     for s in ['""', '""" """', '"hi" "ipython"']:
         nt.assert_false(completer.has_open_quotes(s))
 
 
 @knownfailureif(sys.platform == 'win32', "abspath completions fail on Windows")
 def test_abspath_file_completions():
     ip = get_ipython()
     with TemporaryDirectory() as tmpdir:
         prefix = os.path.join(tmpdir, 'foo')
         suffixes = ['1', '2']
         names = [prefix+s for s in suffixes]
         for n in names:
             open(n, 'w').close()
 
         # Check simple completion
         c = ip.complete(prefix)[1]
         nt.assert_equal(c, names)
 
         # Now check with a function call
         cmd = 'a = f("%s' % prefix
         c = ip.complete(prefix, cmd)[1]
         comp = [prefix+s for s in suffixes]
         nt.assert_equal(c, comp)
 
 
 def test_local_file_completions():
     ip = get_ipython()
     with TemporaryWorkingDirectory():
         prefix = './foo'
         suffixes = ['1', '2']
         names = [prefix+s for s in suffixes]
         for n in names:
             open(n, 'w').close()
 
         # Check simple completion
         c = ip.complete(prefix)[1]
         nt.assert_equal(c, names)
 
         # Now check with a function call
         cmd = 'a = f("%s' % prefix
         c = ip.complete(prefix, cmd)[1]
         comp = set(prefix+s for s in suffixes)
         nt.assert_true(comp.issubset(set(c)))
 
 
 def test_greedy_completions():
     ip = get_ipython()
     ip.ex('a=list(range(5))')
     _,c = ip.complete('.',line='a[0].')
     nt.assert_false('.real' in c,
                     "Shouldn't have completed on a[0]: %s"%c)
     with greedy_completion():
         def _(line, cursor_pos, expect, message):
             _,c = ip.complete('.', line=line, cursor_pos=cursor_pos)
             nt.assert_in(expect, c, message%c)
 
         yield _, 'a[0].', 5, 'a[0].real', "Should have completed on a[0].: %s"
         yield _, 'a[0].r', 6, 'a[0].real', "Should have completed on a[0].r: %s"
         
         if sys.version_info > (3,4):
             yield _, 'a[0].from_', 10, 'a[0].from_bytes', "Should have completed on a[0].from_: %s"
 
 
 
 def test_omit__names():
     # also happens to test IPCompleter as a configurable
     ip = get_ipython()
     ip._hidden_attr = 1
     ip._x = {}
     c = ip.Completer
     ip.ex('ip=get_ipython()')
     cfg = Config()
     cfg.IPCompleter.omit__names = 0
     c.update_config(cfg)
     s,matches = c.complete('ip.')
     nt.assert_in('ip.__str__', matches)
     nt.assert_in('ip._hidden_attr', matches)
     cfg = Config()
     cfg.IPCompleter.omit__names = 1
     c.update_config(cfg)
     s,matches = c.complete('ip.')
     nt.assert_not_in('ip.__str__', matches)
     nt.assert_in('ip._hidden_attr', matches)
     cfg = Config()
     cfg.IPCompleter.omit__names = 2
     c.update_config(cfg)
     s,matches = c.complete('ip.')
     nt.assert_not_in('ip.__str__', matches)
     nt.assert_not_in('ip._hidden_attr', matches)
     s,matches = c.complete('ip._x.')
     nt.assert_in('ip._x.keys', matches)
     del ip._hidden_attr
 
 
 def test_limit_to__all__False_ok():
     ip = get_ipython()
     c = ip.Completer
     ip.ex('class D: x=24')
     ip.ex('d=D()')
     cfg = Config()
     cfg.IPCompleter.limit_to__all__ = False
     c.update_config(cfg)
     s, matches = c.complete('d.')
     nt.assert_in('d.x', matches)
 
 
 def test_get__all__entries_ok():
     class A(object):
         __all__ = ['x', 1]
     words = completer.get__all__entries(A())
     nt.assert_equal(words, ['x'])
 
 
 def test_get__all__entries_no__all__ok():
     class A(object):
         pass
     words = completer.get__all__entries(A())
     nt.assert_equal(words, [])
 
 
 def test_func_kw_completions():
     ip = get_ipython()
     c = ip.Completer
     ip.ex('def myfunc(a=1,b=2): return a+b')
     s, matches = c.complete(None, 'myfunc(1,b')
     nt.assert_in('b=', matches)
     # Simulate completing with cursor right after b (pos==10):
     s, matches = c.complete(None, 'myfunc(1,b)', 10)
     nt.assert_in('b=', matches)
     s, matches = c.complete(None, 'myfunc(a="escaped\\")string",b')
     nt.assert_in('b=', matches)
     #builtin function
     s, matches = c.complete(None, 'min(k, k')
     nt.assert_in('key=', matches)
 
 
 def test_default_arguments_from_docstring():
     ip = get_ipython()
     c = ip.Completer
     kwd = c._default_arguments_from_docstring(
         'min(iterable[, key=func]) -> value')
     nt.assert_equal(kwd, ['key'])
     #with cython type etc
     kwd = c._default_arguments_from_docstring(
         'Minuit.migrad(self, int ncall=10000, resume=True, int nsplit=1)\n')
     nt.assert_equal(kwd, ['ncall', 'resume', 'nsplit'])
     #white spaces
     kwd = c._default_arguments_from_docstring(
         '\n Minuit.migrad(self, int ncall=10000, resume=True, int nsplit=1)\n')
     nt.assert_equal(kwd, ['ncall', 'resume', 'nsplit'])
 
 def test_line_magics():
     ip = get_ipython()
     c = ip.Completer
     s, matches = c.complete(None, 'lsmag')
     nt.assert_in('%lsmagic', matches)
     s, matches = c.complete(None, '%lsmag')
     nt.assert_in('%lsmagic', matches)
 
 
 def test_cell_magics():
     from IPython.core.magic import register_cell_magic
 
     @register_cell_magic
     def _foo_cellm(line, cell):
         pass
     
     ip = get_ipython()
     c = ip.Completer
 
     s, matches = c.complete(None, '_foo_ce')
     nt.assert_in('%%_foo_cellm', matches)
     s, matches = c.complete(None, '%%_foo_ce')
     nt.assert_in('%%_foo_cellm', matches)
 
 
 def test_line_cell_magics():
     from IPython.core.magic import register_line_cell_magic
 
     @register_line_cell_magic
     def _bar_cellm(line, cell):
         pass
     
     ip = get_ipython()
     c = ip.Completer
 
     # The policy here is trickier, see comments in completion code.  The
     # returned values depend on whether the user passes %% or not explicitly,
     # and this will show a difference if the same name is both a line and cell
     # magic.
     s, matches = c.complete(None, '_bar_ce')
     nt.assert_in('%_bar_cellm', matches)
     nt.assert_in('%%_bar_cellm', matches)
     s, matches = c.complete(None, '%_bar_ce')
     nt.assert_in('%_bar_cellm', matches)
     nt.assert_in('%%_bar_cellm', matches)
     s, matches = c.complete(None, '%%_bar_ce')
     nt.assert_not_in('%_bar_cellm', matches)
     nt.assert_in('%%_bar_cellm', matches)
 
 
 def test_magic_completion_order():
 
     ip = get_ipython()
     c = ip.Completer
 
     # Test ordering of magics and non-magics with the same name
     # We want the non-magic first
 
     # Before importing matplotlib, there should only be one option:
 
     text, matches = c.complete('mat')
     nt.assert_equal(matches, ["%matplotlib"])
 
 
     ip.run_cell("matplotlib = 1")  # introduce name into namespace
 
     # After the import, there should be two options, ordered like this:
     text, matches = c.complete('mat')
     nt.assert_equal(matches, ["matplotlib", "%matplotlib"])
 
 
     ip.run_cell("timeit = 1")  # define a user variable called 'timeit'
 
     # Order of user variable and line and cell magics with same name:
     text, matches = c.complete('timeit')
     nt.assert_equal(matches, ["timeit", "%timeit","%%timeit"])
 
 
 def test_dict_key_completion_string():
     """Test dictionary key completion for string keys"""
     ip = get_ipython()
     complete = ip.Completer.complete
 
     ip.user_ns['d'] = {'abc': None}
 
     # check completion at different stages
     _, matches = complete(line_buffer="d[")
     nt.assert_in("'abc'", matches)
     nt.assert_not_in("'abc']", matches)
 
     _, matches = complete(line_buffer="d['")
     nt.assert_in("abc", matches)
     nt.assert_not_in("abc']", matches)
 
     _, matches = complete(line_buffer="d['a")
     nt.assert_in("abc", matches)
     nt.assert_not_in("abc']", matches)
 
     # check use of different quoting
     _, matches = complete(line_buffer="d[\"")
     nt.assert_in("abc", matches)
     nt.assert_not_in('abc\"]', matches)
 
     _, matches = complete(line_buffer="d[\"a")
     nt.assert_in("abc", matches)
     nt.assert_not_in('abc\"]', matches)
 
     # check sensitivity to following context
     _, matches = complete(line_buffer="d[]", cursor_pos=2)
     nt.assert_in("'abc'", matches)
 
     _, matches = complete(line_buffer="d['']", cursor_pos=3)
     nt.assert_in("abc", matches)
     nt.assert_not_in("abc'", matches)
     nt.assert_not_in("abc']", matches)
 
     # check multiple solutions are correctly returned and that noise is not
     ip.user_ns['d'] = {'abc': None, 'abd': None, 'bad': None, object(): None,
                        5: None}
 
     _, matches = complete(line_buffer="d['a")
     nt.assert_in("abc", matches)
     nt.assert_in("abd", matches)
     nt.assert_not_in("bad", matches)
     assert not any(m.endswith((']', '"', "'")) for m in matches), matches
 
     # check escaping and whitespace
     ip.user_ns['d'] = {'a\nb': None, 'a\'b': None, 'a"b': None, 'a word': None}
     _, matches = complete(line_buffer="d['a")
     nt.assert_in("a\\nb", matches)
     nt.assert_in("a\\'b", matches)
     nt.assert_in("a\"b", matches)
     nt.assert_in("a word", matches)
     assert not any(m.endswith((']', '"', "'")) for m in matches), matches
 
     # - can complete on non-initial word of the string
     _, matches = complete(line_buffer="d['a w")
     nt.assert_in("word", matches)
 
     # - understands quote escaping
     _, matches = complete(line_buffer="d['a\\'")
     nt.assert_in("b", matches)
 
     # - default quoting should work like repr
     _, matches = complete(line_buffer="d[")
     nt.assert_in("\"a'b\"", matches)
 
     # - when opening quote with ", possible to match with unescaped apostrophe
     _, matches = complete(line_buffer="d[\"a'")
     nt.assert_in("b", matches)
 
     # need to not split at delims that readline won't split at
     if '-' not in ip.Completer.splitter.delims:
         ip.user_ns['d'] = {'before-after': None}
         _, matches = complete(line_buffer="d['before-af")
         nt.assert_in('before-after', matches)
 
 def test_dict_key_completion_contexts():
     """Test expression contexts in which dict key completion occurs"""
     ip = get_ipython()
     complete = ip.Completer.complete
     d = {'abc': None}
     ip.user_ns['d'] = d
 
     class C:
         data = d
     ip.user_ns['C'] = C
     ip.user_ns['get'] = lambda: d
 
     def assert_no_completion(**kwargs):
         _, matches = complete(**kwargs)
         nt.assert_not_in('abc', matches)
         nt.assert_not_in('abc\'', matches)
         nt.assert_not_in('abc\']', matches)
         nt.assert_not_in('\'abc\'', matches)
         nt.assert_not_in('\'abc\']', matches)
 
     def assert_completion(**kwargs):
         _, matches = complete(**kwargs)
         nt.assert_in("'abc'", matches)
         nt.assert_not_in("'abc']", matches)
 
     # no completion after string closed, even if reopened
     assert_no_completion(line_buffer="d['a'")
     assert_no_completion(line_buffer="d[\"a\"")
     assert_no_completion(line_buffer="d['a' + ")
     assert_no_completion(line_buffer="d['a' + '")
 
     # completion in non-trivial expressions
     assert_completion(line_buffer="+ d[")
     assert_completion(line_buffer="(d[")
     assert_completion(line_buffer="C.data[")
 
     # greedy flag
     def assert_completion(**kwargs):
         _, matches = complete(**kwargs)
         nt.assert_in("get()['abc']", matches)
     
     assert_no_completion(line_buffer="get()[")
     with greedy_completion():
         assert_completion(line_buffer="get()[")
         assert_completion(line_buffer="get()['")
         assert_completion(line_buffer="get()['a")
         assert_completion(line_buffer="get()['ab")
         assert_completion(line_buffer="get()['abc")
 
 
 
 def test_dict_key_completion_bytes():
     """Test handling of bytes in dict key completion"""
     ip = get_ipython()
     complete = ip.Completer.complete
 
     ip.user_ns['d'] = {'abc': None, b'abd': None}
 
     _, matches = complete(line_buffer="d[")
     nt.assert_in("'abc'", matches)
     nt.assert_in("b'abd'", matches)
 
     if False:  # not currently implemented
         _, matches = complete(line_buffer="d[b")
         nt.assert_in("b'abd'", matches)
         nt.assert_not_in("b'abc'", matches)
 
         _, matches = complete(line_buffer="d[b'")
         nt.assert_in("abd", matches)
         nt.assert_not_in("abc", matches)
 
         _, matches = complete(line_buffer="d[B'")
         nt.assert_in("abd", matches)
         nt.assert_not_in("abc", matches)
 
         _, matches = complete(line_buffer="d['")
         nt.assert_in("abc", matches)
         nt.assert_not_in("abd", matches)
 
 
 def test_dict_key_completion_unicode_py3():
     """Test handling of unicode in dict key completion"""
     ip = get_ipython()
     complete = ip.Completer.complete
 
     ip.user_ns['d'] = {u'a\u05d0': None}
 
     # query using escape
     if sys.platform != 'win32':
         # Known failure on Windows
         _, matches = complete(line_buffer="d['a\\u05d0")
         nt.assert_in("u05d0", matches)  # tokenized after \\
 
     # query using character
     _, matches = complete(line_buffer="d['a\u05d0")
     nt.assert_in(u"a\u05d0", matches)
     
     with greedy_completion():
         # query using escape
         _, matches = complete(line_buffer="d['a\\u05d0")
         nt.assert_in("d['a\\u05d0']", matches)  # tokenized after \\
 
         # query using character
         _, matches = complete(line_buffer="d['a\u05d0")
         nt.assert_in(u"d['a\u05d0']", matches)
         
 
 
 @dec.skip_without('numpy')
 def test_struct_array_key_completion():
     """Test dict key completion applies to numpy struct arrays"""
     import numpy
     ip = get_ipython()
     complete = ip.Completer.complete
     ip.user_ns['d'] = numpy.array([], dtype=[('hello', 'f'), ('world', 'f')])
     _, matches = complete(line_buffer="d['")
     nt.assert_in("hello", matches)
     nt.assert_in("world", matches)
     # complete on the numpy struct itself
     dt = numpy.dtype([('my_head', [('my_dt', '>u4'), ('my_df', '>u4')]),
                       ('my_data', '>f4', 5)])
     x = numpy.zeros(2, dtype=dt)
     ip.user_ns['d'] = x[1]
     _, matches = complete(line_buffer="d['")
     nt.assert_in("my_head", matches)
     nt.assert_in("my_data", matches)
     # complete on a nested level
     with greedy_completion():
         ip.user_ns['d'] = numpy.zeros(2, dtype=dt)
         _, matches = complete(line_buffer="d[1]['my_head']['")
         nt.assert_true(any(["my_dt" in m for m in matches]))
         nt.assert_true(any(["my_df" in m for m in matches]))
 
 
 @dec.skip_without('pandas')
 def test_dataframe_key_completion():
     """Test dict key completion applies to pandas DataFrames"""
     import pandas
     ip = get_ipython()
     complete = ip.Completer.complete
     ip.user_ns['d'] = pandas.DataFrame({'hello': [1], 'world': [2]})
     _, matches = complete(line_buffer="d['")
     nt.assert_in("hello", matches)
     nt.assert_in("world", matches)
 
 
 def test_dict_key_completion_invalids():
     """Smoke test cases dict key completion can't handle"""
     ip = get_ipython()
     complete = ip.Completer.complete
 
     ip.user_ns['no_getitem'] = None
     ip.user_ns['no_keys'] = []
     ip.user_ns['cant_call_keys'] = dict
     ip.user_ns['empty'] = {}
     ip.user_ns['d'] = {'abc': 5}
 
     _, matches = complete(line_buffer="no_getitem['")
     _, matches = complete(line_buffer="no_keys['")
     _, matches = complete(line_buffer="cant_call_keys['")
     _, matches = complete(line_buffer="empty['")
     _, matches = complete(line_buffer="name_error['")
     _, matches = complete(line_buffer="d['\\")  # incomplete escape
 
 class KeyCompletable(object):
     def __init__(self, things=()):
         self.things = things
 
     def _ipython_key_completions_(self):
         return list(self.things)
 
 def test_object_key_completion():
     ip = get_ipython()
     ip.user_ns['key_completable'] = KeyCompletable(['qwerty', 'qwick'])
 
     _, matches = ip.Completer.complete(line_buffer="key_completable['qw")
     nt.assert_in('qwerty', matches)
     nt.assert_in('qwick', matches)
 
 
+def test_tryimport():
+    """
+    Test that try-import don't crash on trailing dot, and import modules before
+    """
+    from IPython.core.completerlib import try_import
+    assert(try_import("IPython."))
+
+
 def test_aimport_module_completer():
     ip = get_ipython()
     _, matches = ip.complete('i', '%aimport i')
     nt.assert_in('io', matches)
     nt.assert_not_in('int', matches)
 
 def test_nested_import_module_completer():
     ip = get_ipython()
     _, matches = ip.complete(None, 'import IPython.co', 17)
     nt.assert_in('IPython.core', matches)
     nt.assert_not_in('import IPython.core', matches)
     nt.assert_not_in('IPython.display', matches)
 
 def test_import_module_completer():
     ip = get_ipython()
     _, matches = ip.complete('i', 'import i')
     nt.assert_in('io', matches)
     nt.assert_not_in('int', matches)
 
 def test_from_module_completer():
     ip = get_ipython()
     _, matches = ip.complete('B', 'from io import B', 16)
     nt.assert_in('BytesIO', matches)
     nt.assert_not_in('BaseException', matches)