New "with ignored(*exceptions)" context manager

jedi/api_classes.py

@@ -3,6 +3,7 @@ The :mod:`api_classes` module contains the return classes of the API. These
 classes are the much bigger part of the whole API, because they contain the
 interesting information about completion and goto operations.
 """
+from __future__ import with_statement
 
 import re
 import os
@@ -11,6 +12,7 @@ import functools
 
 from jedi._compatibility import unicode, next
 from jedi import settings
+from jedi import common
 from jedi import parsing_representation as pr
 from jedi import cache
 import keywords
@@ -144,10 +146,8 @@ class BaseDefinition(object):
         if not isinstance(self.definition, keywords.Keyword):
             par = self.definition
             while par is not None:
-                try:
+                with common.ignored(AttributeError):
                     path.insert(0, par.name)
-                except AttributeError:
-                    pass
                 par = par.parent
         return path
 
@@ -295,10 +295,8 @@ class BaseDefinition(object):
         if not path:
             return None  # for keywords the path is empty
 
-        try:
+        with common.ignored(KeyError):
             path[0] = self._mapping[path[0]]
-        except KeyError:
-            pass
         for key, repl in self._tuple_mapping.items():
             if tuple(path[:len(key)]) == key:
                 path = [repl] + path[len(key):]

jedi/cache.py

@@ -30,6 +30,7 @@ import shutil
 
 from jedi._compatibility import json
 from jedi import settings
+from jedi import common
 from jedi import debug
 
 # memoize caches will be deleted after every action
@@ -148,12 +149,10 @@ def cache_function_definition(stmt):
 
 def cache_star_import(func):
     def wrapper(scope, *args, **kwargs):
-        try:
+        with common.ignored(KeyError):
             mods = star_import_cache[scope]
             if mods[0] + settings.star_import_cache_validity > time.time():
                 return mods[1]
-        except KeyError:
-            pass
         # cache is too old and therefore invalid or not available
         invalidate_star_import_cache(scope)
         mods = func(scope, *args, **kwargs)
@@ -165,15 +164,13 @@ def cache_star_import(func):
 
 def invalidate_star_import_cache(module, only_main=False):
     """ Important if some new modules are being reparsed """
-    try:
+    with common.ignored(KeyError):
         t, mods = star_import_cache[module]
 
         del star_import_cache[module]
 
         for m in mods:
             invalidate_star_import_cache(m, only_main=True)
-    except KeyError:
-        pass
 
     if not only_main:
         # We need a list here because otherwise the list is being changed

jedi/common.py

@@ -163,3 +163,13 @@ def indent_block(text, indention='    '):
         text = text[:-1]
     lines = text.split('\n')
     return '\n'.join(map(lambda s: indention + s, lines)) + temp
+
+
+@contextlib.contextmanager
+def ignored(*exceptions):
+    """Context manager that ignores all of the specified exceptions. This will
+    be in the standard library starting with Python 3.4."""
+    try:
+        yield
+    except exceptions:
+        pass

jedi/dynamic.py

@@ -59,6 +59,7 @@ from jedi import cache
 from jedi import parsing_representation as pr
 from jedi import modules
 from jedi import settings
+from jedi import common
 from jedi import debug
 from jedi import fast_parser
 import api_classes
@@ -487,10 +488,8 @@ def related_name_add_import_modules(definitions, search_name):
     for d in definitions:
         if isinstance(d.parent, pr.Import):
             s = imports.ImportPath(d.parent, direct_resolve=True)
-            try:
+            with common.ignored(IndexError):
                 new.add(s.follow(is_goto=True)[0])
-            except IndexError:
-                pass
     return set(definitions) | new
 
 

jedi/evaluate.py

@@ -68,6 +68,7 @@ backtracking algorithm.
 
 .. todo:: nonlocal statement, needed or can be ignored? (py3k)
 """
+from __future__ import with_statement
 
 import sys
 import itertools
@@ -429,11 +430,9 @@ def find_name(scope, name_str, position=None, search_global=False,
             if isinstance(scope, (er.Instance, er.Class)) \
                                 and hasattr(r, 'get_descriptor_return'):
                 # handle descriptors
-                try:
+                with common.ignored(KeyError):
                     res_new += r.get_descriptor_return(scope)
                     continue
-                except KeyError:
-                    pass
             res_new.append(r)
         return res_new
 
@@ -462,19 +461,15 @@ def check_getattr(inst, name_str):
     # str is important to lose the NamePart!
     module = builtin.Builtin.scope
     name = pr.Call(module, str(name_str), pr.Call.STRING, (0, 0), inst)
-    try:
+    with common.ignored(KeyError):
         result = inst.execute_subscope_by_name('__getattr__', [name])
-    except KeyError:
-        pass
     if not result:
         # this is a little bit special. `__getattribute__` is executed
         # before anything else. But: I know no use case, where this
         # could be practical and the jedi would return wrong types. If
         # you ever have something, let me know!
-        try:
+        with common.ignored(KeyError):
             result = inst.execute_subscope_by_name('__getattribute__', [name])
-        except KeyError:
-            pass
     return result
 
 
@@ -536,10 +531,8 @@ def assign_tuples(tup, results, seek_name):
                 debug.warning("invalid tuple lookup %s of result %s in %s"
                                     % (tup, results, seek_name))
             else:
-                try:
+                with common.ignored(IndexError):
                     types += func(index)
-                except IndexError:
-                    pass
         return types
 
     result = []
@@ -648,11 +641,9 @@ def follow_call_list(call_list, follow_array=False):
                             call = next(calls_iterator)
                         except StopIteration:
                             break
-                        try:
+                        with common.ignored(AttributeError):
                             if str(call.name) == 'else':
                                 break
-                        except AttributeError:
-                            pass
                     continue
                 result += follow_call(call)
             elif call == '*':

jedi/evaluate_representation.py

@@ -9,6 +9,8 @@ instantiated. This class represents these cases.
 So, why is there also a ``Class`` class here? Well, there are decorators and
 they change classes in Python 3.
 """
+from __future__ import with_statement
+
 import copy
 import itertools
 
@@ -61,10 +63,8 @@ class Instance(use_metaclass(cache.CachedMetaClass, Executable)):
         else:
             # need to execute the __init__ function, because the dynamic param
             # searching needs it.
-            try:
+            with common.ignored(KeyError):
                 self.execute_subscope_by_name('__init__', self.var_args)
-            except KeyError:
-                pass
         # Generated instances are classes that are just generated by self
         # (No var_args) used.
         self.is_generated = False
@@ -804,10 +804,8 @@ class Array(use_metaclass(cache.CachedMetaClass, pr.Base)):
                 if isinstance(index, Instance) \
                             and str(index.name) in ['int', 'str'] \
                             and len(index.var_args) == 1:
-                    try:
+                    with common.ignored(KeyError, IndexError):
                         return self.get_exact_index_types(index.var_args[0])
-                    except (KeyError, IndexError):
-                        pass
 
         result = list(self._follow_values(self._array.values))
         result += dynamic.check_array_additions(self)

jedi/helpers.py

@@ -1,5 +1,8 @@
+from __future__ import with_statement
+
 import copy
 
+from jedi import common
 from jedi import parsing_representation as pr
 
 
@@ -21,13 +24,11 @@ def fast_parent_copy(obj):
 
         before = ()
         for cls in new_obj.__class__.__mro__:
-            try:
+            with common.ignored(AttributeError):
                 if before == cls.__slots__:
                     continue
                 before = cls.__slots__
                 items += [(n, getattr(new_obj, n)) for n in before]
-            except AttributeError:
-                pass
 
         for key, value in items:
             # replace parent (first try _parent and then parent)
@@ -35,10 +36,8 @@ def fast_parent_copy(obj):
                 if key == 'parent' and '_parent' in items:
                     # parent can be a property
                     continue
-                try:
+                with common.ignored(KeyError):
                     setattr(new_obj, key, new_elements[value])
-                except KeyError:
-                    pass
             elif key in ['parent_function', 'use_as_parent', '_sub_module']:
                 continue
             elif isinstance(value, list):

jedi/imports.py

@@ -11,7 +11,6 @@ correct implementation is delegated to _compatibility.
 This module also supports import autocompletion, which means to complete
 statements like ``from datetim`` (curser at the end would return ``datetime``).
 """
-
 from __future__ import with_statement
 
 import os
@@ -21,6 +20,7 @@ import itertools
 
 from jedi._compatibility import find_module
 from jedi import modules
+from jedi import common
 from jedi import debug
 from jedi import parsing_representation as pr
 from jedi import cache
@@ -122,11 +122,9 @@ class ImportPath(pr.Base):
 
                     if self.import_stmt.relative_count:
                         rel_path = self.get_relative_path() + '/__init__.py'
-                        try:
+                        with common.ignored(IOError):
                             m = modules.Module(rel_path)
                             names += m.parser.module.get_defined_names()
-                        except IOError:
-                            pass
             else:
                 if on_import_stmt and isinstance(scope, pr.Module) \
                                         and scope.path.endswith('__init__.py'):
@@ -274,10 +272,8 @@ class ImportPath(pr.Base):
                                 and len(self.import_path) == 1:
                     # follow `from . import some_variable`
                     rel_path = self.get_relative_path()
-                    try:
+                    with common.ignored(ImportError):
                         current_namespace = follow_str(rel_path, '__init__')
-                    except ImportError:
-                        pass
                 if current_namespace[1]:
                     rest = self.import_path[i:]
                 else:

jedi/keywords.py

@@ -1,7 +1,10 @@
+from __future__ import with_statement
+
 import pydoc
 import keyword
 
 from jedi._compatibility import is_py3k
+from jedi import common
 import builtin
 
 try:
@@ -63,12 +66,10 @@ def imitate_pydoc(string):
     # with unicode strings)
     string = str(string)
     h = pydoc.help
-    try:
+    with common.ignored(KeyError):
         # try to access symbols
         string = h.symbols[string]
         string, _, related = string.partition(' ')
-    except KeyError:
-        pass
 
     get_target = lambda s: h.topics.get(s, h.keywords.get(s))
     while isinstance(string, str):

jedi/modules.py

@@ -27,6 +27,7 @@ from jedi import parsing_representation as pr
 from jedi import fast_parser
 from jedi import debug
 from jedi import settings
+from jedi import common
 
 
 class CachedModule(object):
@@ -107,11 +108,9 @@ class ModuleWithCursor(Module):
     def parser(self):
         """ get the parser lazy """
         if not self._parser:
-            try:
+            with common.ignored(KeyError):
                 parser = cache.parser_cache[self.path].parser
                 cache.invalidate_star_import_cache(parser.module)
-            except KeyError:
-                pass
             # Call the parser already here, because it will be used anyways.
             # Also, the position is here important (which will not be used by
             # default), therefore fill the cache here.
@@ -348,10 +347,8 @@ def sys_path_with_modifications(module):
         return []  # support for modules without a path is intentionally bad.
 
     curdir = os.path.abspath(os.curdir)
-    try:
+    with common.ignored(OSError):
         os.chdir(os.path.dirname(module.path))
-    except OSError:
-        pass
 
     result = check_module(module)
     result += detect_django_path(module.path)
@@ -372,12 +369,10 @@ def detect_django_path(module_path):
         else:
             module_path = new
 
-        try:
+        with common.ignored(IOError):
             with open(module_path + os.path.sep + 'manage.py'):
                 debug.dbg('Found django path: %s' % module_path)
                 result.append(module_path)
-        except IOError:
-            pass
     return result
 
 

jedi/parsing.py

@@ -15,6 +15,7 @@ within the statement. This lowers memory usage and cpu time and reduces the
 complexity of the ``Parser`` (there's another parser sitting inside
 ``Statement``, which produces ``Array`` and ``Call``).
 """
+from __future__ import with_statement
 
 import tokenize
 import keyword
@@ -396,7 +397,7 @@ class Parser(object):
             self._check_user_stmt(stmt)
 
         # Attribute docstring (PEP 257) support
-        try:
+        with common.ignored(IndexError, AttributeError):
             # If string literal is being parsed
             first_tok = stmt.token_list[0]
             if (not stmt.set_vars and
@@ -405,8 +406,6 @@ class Parser(object):
                 first_tok[0] == tokenize.STRING):
                 # ... then set it as a docstring
                 self.scope.statements[-1].add_docstr(first_tok[1])
-        except (IndexError, AttributeError):
-            pass
 
         if tok in always_break + not_first_break:
             self._gen.push_last_back()

jedi/parsing_representation.py

@@ -34,6 +34,7 @@ statements in this scope.  Check this out:
 See also :attr:`Scope.subscopes` and :attr:`Scope.statements`.
 
 """
+from __future__ import with_statement
 
 import os
 import re
@@ -1280,11 +1281,8 @@ class Array(Call):
         inner = []
         for i, stmt in enumerate(self.values):
             s = ''
-            try:
+            with common.ignored(IndexError):
                 key = self.keys[i]
-            except IndexError:
-                pass
-            else:
                 s += key.get_code(new_line=False) + ': '
             s += stmt.get_code(new_line=False)
             inner.append(s)

jedi/refactoring.py

@@ -12,11 +12,11 @@ following functions (sometimes bug-prone):
 - extract variable
 - inline variable
 """
-
 from __future__ import with_statement
 
 import difflib
 
+from jedi import common
 from jedi import modules
 from jedi import helpers
 from jedi import parsing_representation as pr
@@ -168,7 +168,7 @@ def inline(script):
     dct = {}
 
     definitions = script.goto()
-    try:
+    with common.ignored(AssertionError):
         assert len(definitions) == 1
         stmt = definitions[0].definition
         related_names = script.related_names()
@@ -202,7 +202,4 @@ def inline(script):
         else:
             new_lines.pop(index)
 
-    except AssertionError:
-        pass
-
     return Refactoring(dct)