diff --git a/.coveragerc b/.coveragerc
index c48bafc2..939a3175 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -1,6 +1,7 @@
 [run]
 omit =
     jedi/_compatibility.py
+    jedi/evaluate/site.py
 
 [report]
 # Regexes for lines to exclude from consideration
diff --git a/.travis.yml b/.travis.yml
index 810b7f58..876af276 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 language: python
+sudo: false
 env:
     - TOXENV=py26
     - TOXENV=py27
diff --git a/AUTHORS.txt b/AUTHORS.txt
index 64aae316..bc258d6b 100644
--- a/AUTHORS.txt
+++ b/AUTHORS.txt
@@ -33,5 +33,6 @@ Savor d'Isavano (@KenetJervet) <newelevenken@163.com>
 Phillip Berndt (@phillipberndt) <phillip.berndt@gmail.com>
 Ian Lee (@IanLee1521) <IanLee1521@gmail.com>
 Farkhad Khatamov (@hatamov) <comsgn@gmail.com>
+Kevin Kelley (@kelleyk) <kelleyk@kelleyk.net>
 
 Note: (@user) means a github user name.
diff --git a/conftest.py b/conftest.py
index 480a2510..2567fcde 100644
--- a/conftest.py
+++ b/conftest.py
@@ -1,8 +1,9 @@
 import tempfile
 import shutil
 
-import jedi
+import pytest
 
+import jedi
 
 collect_ignore = ["setup.py"]
 
@@ -47,3 +48,25 @@ def pytest_unconfigure(config):
     global jedi_cache_directory_orig, jedi_cache_directory_temp
     jedi.settings.cache_directory = jedi_cache_directory_orig
     shutil.rmtree(jedi_cache_directory_temp)
+
+
+@pytest.fixture(scope='session')
+def clean_jedi_cache(request):
+    """
+    Set `jedi.settings.cache_directory` to a temporary directory during test.
+
+    Note that you can't use built-in `tmpdir` and `monkeypatch`
+    fixture here because their scope is 'function', which is not used
+    in 'session' scope fixture.
+
+    This fixture is activated in ../pytest.ini.
+    """
+    from jedi import settings
+    old = settings.cache_directory
+    tmp = tempfile.mkdtemp(prefix='jedi-test-')
+    settings.cache_directory = tmp
+
+    @request.addfinalizer
+    def restore():
+        settings.cache_directory = old
+        shutil.rmtree(tmp)
diff --git a/jedi/_compatibility.py b/jedi/_compatibility.py
index 1a1e943f..60c9dcb5 100644
--- a/jedi/_compatibility.py
+++ b/jedi/_compatibility.py
@@ -25,7 +25,7 @@ def find_module_py33(string, path=None):
         except ValueError as e:
             # See #491. Importlib might raise a ValueError, to avoid this, we
             # just raise an ImportError to fix the issue.
-            raise ImportError("Originally ValueError: " + e.message)
+            raise ImportError("Originally ValueError: " + str(e))
 
     if loader is None:
         raise ImportError("Couldn't find a loader for {0}".format(string))
diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index bff52d77..b8f62171 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -34,6 +34,7 @@ from jedi.evaluate.param import try_iter_content
 from jedi.evaluate.cache import memoize_default
 from jedi.evaluate.helpers import FakeName, get_module_names
 from jedi.evaluate.finder import global_names_dict_generator, filter_definition_names
+from jedi.evaluate.sys_path import get_venv_path
 
 # Jedi uses lots and lots of recursion. By setting this a little bit higher, we
 # can remove some "maximum recursion depth" errors.
@@ -58,6 +59,18 @@ class Script(object):
     You can either use the ``source`` parameter or ``path`` to read a file.
     Usually you're going to want to use both of them (in an editor).
 
+    The script might be analyzed in a different ``sys.path`` than |jedi|:
+
+    - if `sys_path` parameter is not ``None``, it will be used as ``sys.path``
+      for the script;
+
+    - if `sys_path` parameter is ``None`` and ``VIRTUAL_ENV`` environment
+      variable is defined, ``sys.path`` for the specified environment will be
+      guessed (see :func:`jedi.evaluate.sys_path.get_venv_path`) and used for
+      the script;
+
+    - otherwise ``sys.path`` will match that of |jedi|.
+
     :param source: The source code of the current file, separated by newlines.
     :type source: str
     :param line: The line to perform actions on (starting with 1).
@@ -73,9 +86,13 @@ class Script(object):
     :param source_encoding: The encoding of ``source``, if it is not a
         ``unicode`` object (default ``'utf-8'``).
     :type encoding: str
+    :param sys_path: ``sys.path`` to use during analysis of the script
+    :type sys_path: list
+
     """
     def __init__(self, source=None, line=None, column=None, path=None,
-                 encoding='utf-8', source_path=None, source_encoding=None):
+                 encoding='utf-8', source_path=None, source_encoding=None,
+                 sys_path=None):
         if source_path is not None:
             warnings.warn("Use path instead of source_path.", DeprecationWarning)
             path = source_path
@@ -109,7 +126,11 @@ class Script(object):
         self._parser = UserContextParser(self._grammar, self.source, path,
                                          self._pos, self._user_context,
                                          self._parsed_callback)
-        self._evaluator = Evaluator(self._grammar)
+        if sys_path is None:
+            venv = os.getenv('VIRTUAL_ENV')
+            if venv:
+                sys_path = list(get_venv_path(venv))
+        self._evaluator = Evaluator(self._grammar, sys_path=sys_path)
         debug.speed('init')
 
     def _parsed_callback(self, parser):
diff --git a/jedi/api/classes.py b/jedi/api/classes.py
index e5926ca8..0eb24664 100644
--- a/jedi/api/classes.py
+++ b/jedi/api/classes.py
@@ -336,7 +336,7 @@ class BaseDefinition(object):
             raise AttributeError()
         followed = followed[0]  # only check the first one.
 
-        if followed.type == 'funcdef':
+        if followed.type in ('funcdef', 'lambda'):
             if isinstance(followed, er.InstanceElement):
                 params = followed.params[1:]
             else:
diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index c771a044..bf2d619f 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -61,6 +61,7 @@ that are not used are just being ignored.
 """
 
 import copy
+import sys
 from itertools import chain
 
 from jedi.parser import tree
@@ -79,7 +80,7 @@ from jedi.evaluate import helpers
 
 
 class Evaluator(object):
-    def __init__(self, grammar):
+    def __init__(self, grammar, sys_path=None):
         self.grammar = grammar
         self.memoize_cache = {}  # for memoize decorators
         # To memorize modules -> equals `sys.modules`.
@@ -91,6 +92,14 @@ class Evaluator(object):
         self.predefined_if_name_dict_dict = {}
         self.is_analysis = False
 
+        if sys_path is None:
+            sys_path = sys.path
+        self.sys_path = copy.copy(sys_path)
+        try:
+            self.sys_path.remove('')
+        except ValueError:
+            pass
+
     def wrap(self, element):
         if isinstance(element, tree.Class):
             return er.Class(self, element)
diff --git a/jedi/evaluate/compiled/__init__.py b/jedi/evaluate/compiled/__init__.py
index a28fed7f..f8af842b 100644
--- a/jedi/evaluate/compiled/__init__.py
+++ b/jedi/evaluate/compiled/__init__.py
@@ -10,7 +10,6 @@ from functools import partial
 from jedi._compatibility import builtins as _builtins, unicode
 from jedi import debug
 from jedi.cache import underscore_memoization, memoize_method
-from jedi.evaluate.sys_path import get_sys_path
 from jedi.parser.tree import Param, Base, Operator, zero_position_modifier
 from jedi.evaluate.helpers import FakeName
 from . import fake
@@ -309,15 +308,12 @@ class CompiledName(FakeName):
         pass  # Just ignore this, FakeName tries to overwrite the parent attribute.
 
 
-def dotted_from_fs_path(fs_path, sys_path=None):
+def dotted_from_fs_path(fs_path, sys_path):
     """
     Changes `/usr/lib/python3.4/email/utils.py` to `email.utils`.  I.e.
     compares the path with sys.path and then returns the dotted_path. If the
     path is not in the sys.path, just returns None.
     """
-    if sys_path is None:
-        sys_path = get_sys_path()
-
     if os.path.basename(fs_path).startswith('__init__.'):
         # We are calculating the path. __init__ files are not interesting.
         fs_path = os.path.dirname(fs_path)
@@ -341,13 +337,13 @@ def dotted_from_fs_path(fs_path, sys_path=None):
     return _path_re.sub('', fs_path[len(path):].lstrip(os.path.sep)).replace(os.path.sep, '.')
 
 
-def load_module(path=None, name=None):
+def load_module(evaluator, path=None, name=None):
+    sys_path = evaluator.sys_path
     if path is not None:
-        dotted_path = dotted_from_fs_path(path)
+        dotted_path = dotted_from_fs_path(path, sys_path=sys_path)
     else:
         dotted_path = name
 
-    sys_path = get_sys_path()
     if dotted_path is None:
         p, _, dotted_path = path.partition(os.path.sep)
         sys_path.insert(0, p)
diff --git a/jedi/evaluate/imports.py b/jedi/evaluate/imports.py
index 24e1f110..26ecf272 100644
--- a/jedi/evaluate/imports.py
+++ b/jedi/evaluate/imports.py
@@ -342,7 +342,7 @@ class Importer(object):
             module_file.close()
 
         if module_file is None and not module_path.endswith('.py'):
-            module = compiled.load_module(module_path)
+            module = compiled.load_module(self._evaluator, module_path)
         else:
             module = _load_module(self._evaluator, module_path, source, sys_path)
 
@@ -440,12 +440,15 @@ def _load_module(evaluator, path=None, source=None, sys_path=None):
                 with open(path, 'rb') as f:
                     source = f.read()
         else:
-            return compiled.load_module(path)
+            return compiled.load_module(evaluator, path)
         p = path
         p = fast.FastParser(evaluator.grammar, common.source_to_unicode(source), p)
         cache.save_parser(path, p)
         return p.module
 
+    if sys_path is None:
+        sys_path = evaluator.sys_path
+
     cached = cache.load_parser(path)
     module = load(source) if cached is None else cached.module
     module = evaluator.wrap(module)
diff --git a/jedi/evaluate/site.py b/jedi/evaluate/site.py
new file mode 100644
index 00000000..bf884fae
--- /dev/null
+++ b/jedi/evaluate/site.py
@@ -0,0 +1,110 @@
+"""An adapted copy of relevant site-packages functionality from Python stdlib.
+
+This file contains some functions related to handling site-packages in Python
+with jedi-specific modifications:
+
+- the functions operate on sys_path argument rather than global sys.path
+
+- in .pth files "import ..." lines that allow execution of arbitrary code are
+  skipped to prevent code injection into jedi interpreter
+
+"""
+
+# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
+# 2011, 2012, 2013, 2014, 2015 Python Software Foundation; All Rights Reserved
+
+from __future__ import print_function
+
+import sys
+import os
+
+
+def makepath(*paths):
+    dir = os.path.join(*paths)
+    try:
+        dir = os.path.abspath(dir)
+    except OSError:
+        pass
+    return dir, os.path.normcase(dir)
+
+
+def _init_pathinfo(sys_path):
+    """Return a set containing all existing directory entries from sys_path"""
+    d = set()
+    for dir in sys_path:
+        try:
+            if os.path.isdir(dir):
+                dir, dircase = makepath(dir)
+                d.add(dircase)
+        except TypeError:
+            continue
+    return d
+
+
+def addpackage(sys_path, sitedir, name, known_paths):
+    """Process a .pth file within the site-packages directory:
+       For each line in the file, either combine it with sitedir to a path
+       and add that to known_paths, or execute it if it starts with 'import '.
+    """
+    if known_paths is None:
+        known_paths = _init_pathinfo(sys_path)
+        reset = 1
+    else:
+        reset = 0
+    fullname = os.path.join(sitedir, name)
+    try:
+        f = open(fullname, "r")
+    except OSError:
+        return
+    with f:
+        for n, line in enumerate(f):
+            if line.startswith("#"):
+                continue
+            try:
+                if line.startswith(("import ", "import\t")):
+                    # Change by immerrr: don't evaluate import lines to prevent
+                    # code injection into jedi through pth files.
+                    #
+                    # exec(line)
+                    continue
+                line = line.rstrip()
+                dir, dircase = makepath(sitedir, line)
+                if not dircase in known_paths and os.path.exists(dir):
+                    sys_path.append(dir)
+                    known_paths.add(dircase)
+            except Exception:
+                print("Error processing line {:d} of {}:\n".format(n+1, fullname),
+                      file=sys.stderr)
+                import traceback
+                for record in traceback.format_exception(*sys.exc_info()):
+                    for line in record.splitlines():
+                        print('  '+line, file=sys.stderr)
+                print("\nRemainder of file ignored", file=sys.stderr)
+                break
+    if reset:
+        known_paths = None
+    return known_paths
+
+
+def addsitedir(sys_path, sitedir, known_paths=None):
+    """Add 'sitedir' argument to sys_path if missing and handle .pth files in
+    'sitedir'"""
+    if known_paths is None:
+        known_paths = _init_pathinfo(sys_path)
+        reset = 1
+    else:
+        reset = 0
+    sitedir, sitedircase = makepath(sitedir)
+    if not sitedircase in known_paths:
+        sys_path.append(sitedir)        # Add path component
+        known_paths.add(sitedircase)
+    try:
+        names = os.listdir(sitedir)
+    except OSError:
+        return
+    names = [name for name in names if name.endswith(".pth")]
+    for name in sorted(names):
+        addpackage(sys_path, sitedir, name, known_paths)
+    if reset:
+        known_paths = None
+    return known_paths
diff --git a/jedi/evaluate/sys_path.py b/jedi/evaluate/sys_path.py
index 10cdb34e..a104bce6 100644
--- a/jedi/evaluate/sys_path.py
+++ b/jedi/evaluate/sys_path.py
@@ -1,6 +1,7 @@
 import glob
 import os
 import sys
+from jedi.evaluate.site import addsitedir
 
 from jedi._compatibility import exec_function, unicode
 from jedi.parser import tree
@@ -11,24 +12,51 @@ from jedi import common
 from jedi import cache
 
 
-def get_sys_path():
-    def check_virtual_env(sys_path):
-        """ Add virtualenv's site-packages to the `sys.path`."""
-        venv = os.getenv('VIRTUAL_ENV')
-        if not venv:
-            return
-        venv = os.path.abspath(venv)
-        p = _get_venv_sitepackages(venv)
-        if p not in sys_path:
-            sys_path.insert(0, p)
+def get_venv_path(venv):
+    """Get sys.path for specified virtual environment."""
+    sys_path = _get_venv_path_dirs(venv)
+    with common.ignored(ValueError):
+        sys_path.remove('')
+    sys_path = _get_sys_path_with_egglinks(sys_path)
+    # As of now, get_venv_path_dirs does not scan built-in pythonpath and
+    # user-local site-packages, let's approximate them using path from Jedi
+    # interpreter.
+    return sys_path + sys.path
 
-        # Add all egg-links from the virtualenv.
-        for egg_link in glob.glob(os.path.join(p, '*.egg-link')):
+
+def _get_sys_path_with_egglinks(sys_path):
+    """Find all paths including those referenced by egg-links.
+
+    Egg-link-referenced directories are inserted into path immediately after
+    the directory on which their links were found.  Such directories are not
+    taken into consideration by normal import mechanism, but they are traversed
+    when doing pkg_resources.require.
+    """
+    result = []
+    for p in sys_path:
+        result.append(p)
+        # pkg_resources does not define a specific order for egg-link files
+        # using os.listdir to enumerate them, we're sorting them to have
+        # reproducible tests.
+        for egg_link in sorted(glob.glob(os.path.join(p, '*.egg-link'))):
             with open(egg_link) as fd:
-                sys_path.insert(0, fd.readline().rstrip())
+                for line in fd:
+                    line = line.strip()
+                    if line:
+                        result.append(os.path.join(p, line))
+                        # pkg_resources package only interprets the first
+                        # non-empty line in egg-link files.
+                        break
+    return result
 
-    check_virtual_env(sys.path)
-    return [p for p in sys.path if p != ""]
+
+def _get_venv_path_dirs(venv):
+    """Get sys.path for venv without starting up the interpreter."""
+    venv = os.path.abspath(venv)
+    sitedir = _get_venv_sitepackages(venv)
+    sys_path = []
+    addsitedir(sys_path, sitedir)
+    return sys_path
 
 
 def _get_venv_sitepackages(venv):
@@ -109,7 +137,6 @@ def _paths_from_list_modifications(module_path, trailer1, trailer2):
     name = trailer1.children[1].value
     if name not in ['insert', 'append']:
         return []
-
     arg = trailer2.children[1]
     if name == 'insert' and len(arg.children) in (3, 4):  # Possible trailing comma.
         arg = arg.children[2]
@@ -117,6 +144,9 @@ def _paths_from_list_modifications(module_path, trailer1, trailer2):
 
 
 def _check_module(evaluator, module):
+    """
+    Detect sys.path modifications within module.
+    """
     def get_sys_path_powers(names):
         for name in names:
             power = name.parent.parent
@@ -128,10 +158,12 @@ def _check_module(evaluator, module):
                     if isinstance(n, tree.Name) and n.value == 'path':
                         yield name, power
 
-    sys_path = list(get_sys_path())  # copy
+    sys_path = list(evaluator.sys_path)  # copy
     try:
         possible_names = module.used_names['path']
     except KeyError:
+        # module.used_names is MergedNamesDict whose getitem never throws
+        # keyerror, this is superfluous.
         pass
     else:
         for name, power in get_sys_path_powers(possible_names):
@@ -148,7 +180,7 @@ def sys_path_with_modifications(evaluator, module):
     if module.path is None:
         # Support for modules without a path is bad, therefore return the
         # normal path.
-        return list(get_sys_path())
+        return list(evaluator.sys_path)
 
     curdir = os.path.abspath(os.curdir)
     with common.ignored(OSError):
diff --git a/jedi/parser/tree.py b/jedi/parser/tree.py
index 17d33372..8fea5399 100644
--- a/jedi/parser/tree.py
+++ b/jedi/parser/tree.py
@@ -825,6 +825,15 @@ def _create_params(parent, argslist_list):
 class Function(ClassOrFunc):
     """
     Used to store the parsed contents of a python function.
+
+    Children:
+      0) <Keyword: def>
+      1) <Name>
+      2) parameter list (including open-paren and close-paren <Operator>s)
+      3) <Operator: :>
+      4) Node() representing function body
+      5) ??
+      6) annotation (if present)
     """
     __slots__ = ('listeners',)
     type = 'funcdef'
@@ -837,6 +846,7 @@ class Function(ClassOrFunc):
 
     @property
     def params(self):
+        # Contents of parameter lit minus the leading <Operator: (> and the trailing <Operator: )>.
         return self.children[2].children[1:-1]
 
     @property
@@ -868,10 +878,13 @@ class Function(ClassOrFunc):
 
         :rtype: str
         """
-        func_name = func_name or self.children[1]
-        code = unicode(func_name) + self.children[2].get_code()
+        func_name = func_name or self.name
+        code = unicode(func_name) + self._get_paramlist_code()
         return '\n'.join(textwrap.wrap(code, width))
 
+    def _get_paramlist_code(self):
+        return self.children[2].get_code()
+    
     @property
     def doc(self):
         """ Return a document string including call signature. """
@@ -897,6 +910,12 @@ class Function(ClassOrFunc):
 class Lambda(Function):
     """
     Lambdas are basically trimmed functions, so give it the same interface.
+
+    Children:
+       0) <Keyword: lambda>
+       *) <Param x> for each argument x
+      -2) <Operator: :>
+      -1) Node() representing body
     """
     type = 'lambda'
     __slots__ = ()
@@ -905,9 +924,17 @@ class Lambda(Function):
         # We don't want to call the Function constructor, call its parent.
         super(Function, self).__init__(children)
         self.listeners = set()  # not used here, but in evaluation.
-        lst = self.children[1:-2]  # After `def foo`
+        lst = self.children[1:-2]  # Everything between `lambda` and the `:` operator is a parameter.
         self.children[1:-2] = _create_params(self, lst)
 
+    @property
+    def name(self):
+        # Borrow the position of the <Keyword: lambda> AST node.
+        return Name(self.children[0].position_modifier, '<lambda>', self.children[0].start_pos)
+
+    def _get_paramlist_code(self):
+        return '(' + ''.join(param.get_code() for param in self.params).strip() + ')'
+    
     @property
     def params(self):
         return self.children[1:-2]
@@ -915,6 +942,7 @@ class Lambda(Function):
     def is_generator(self):
         return False
 
+    @property
     def yields(self):
         return []
 
diff --git a/pytest.ini b/pytest.ini
index 3a066302..6fafa946 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -2,7 +2,7 @@
 addopts = --doctest-modules
 
 # Ignore broken files in blackbox test directories
-norecursedirs = .* docs completion refactor absolute_import namespace_package scripts extensions speed static_analysis not_in_sys_path buildout_project egg-link init_extension_module
+norecursedirs = .* docs completion refactor absolute_import namespace_package scripts extensions speed static_analysis not_in_sys_path buildout_project sample_venvs init_extension_module
 
 # Activate `clean_jedi_cache` fixture for all tests.  This should be
 # fine as long as we are using `clean_jedi_cache` as a session scoped
diff --git a/test/conftest.py b/test/conftest.py
index 6b834146..7349279a 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -1,7 +1,5 @@
 import os
-import shutil
 import re
-import tempfile
 
 import pytest
 
@@ -125,25 +123,3 @@ def isolated_jedi_cache(monkeypatch, tmpdir):
     """
     from jedi import settings
     monkeypatch.setattr(settings, 'cache_directory', str(tmpdir))
-
-
-@pytest.fixture(scope='session')
-def clean_jedi_cache(request):
-    """
-    Set `jedi.settings.cache_directory` to a temporary directory during test.
-
-    Note that you can't use built-in `tmpdir` and `monkeypatch`
-    fixture here because their scope is 'function', which is not used
-    in 'session' scope fixture.
-
-    This fixture is activated in ../pytest.ini.
-    """
-    from jedi import settings
-    old = settings.cache_directory
-    tmp = tempfile.mkdtemp(prefix='jedi-test-')
-    settings.cache_directory = tmp
-
-    @request.addfinalizer
-    def restore():
-        settings.cache_directory = old
-        shutil.rmtree(tmp)
diff --git a/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/dir-from-foo-pth/__init__.py b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/dir-from-foo-pth/__init__.py
new file mode 100644
index 00000000..2a1d8700
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/dir-from-foo-pth/__init__.py
@@ -0,0 +1,2 @@
+# This file is here to force git to create the directory, as *.pth files only
+# add existing directories.
diff --git a/test/test_evaluate/egg-link/venv/lib/python3.4/site-packages/egg_link.egg-link b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/egg_link.egg-link
similarity index 100%
rename from test/test_evaluate/egg-link/venv/lib/python3.4/site-packages/egg_link.egg-link
rename to test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/egg_link.egg-link
diff --git a/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/foo.pth b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/foo.pth
new file mode 100644
index 00000000..88501682
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/foo.pth
@@ -0,0 +1 @@
+./dir-from-foo-pth
diff --git a/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/import_smth.pth b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/import_smth.pth
new file mode 100644
index 00000000..72b006a6
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/import_smth.pth
@@ -0,0 +1 @@
+import smth; smth.extend_path()
\ No newline at end of file
diff --git a/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/relative.egg-link b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/relative.egg-link
new file mode 100644
index 00000000..7a9a6156
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/relative.egg-link
@@ -0,0 +1 @@
+./relative/egg-link/path
diff --git a/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/smth.py b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/smth.py
new file mode 100644
index 00000000..3e3008dd
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv27/lib/python2.7/site-packages/smth.py
@@ -0,0 +1,6 @@
+import sys
+sys.path.append('/path/from/smth.py')
+
+
+def extend_path():
+    sys.path.append('/path/from/smth.py:extend_path')
diff --git a/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/dir-from-foo-pth/__init__.py b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/dir-from-foo-pth/__init__.py
new file mode 100644
index 00000000..2a1d8700
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/dir-from-foo-pth/__init__.py
@@ -0,0 +1,2 @@
+# This file is here to force git to create the directory, as *.pth files only
+# add existing directories.
diff --git a/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/egg_link.egg-link b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/egg_link.egg-link
new file mode 100644
index 00000000..dde9b7d5
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/egg_link.egg-link
@@ -0,0 +1 @@
+/path/from/egg-link
diff --git a/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/foo.pth b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/foo.pth
new file mode 100644
index 00000000..88501682
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/foo.pth
@@ -0,0 +1 @@
+./dir-from-foo-pth
diff --git a/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/import_smth.pth b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/import_smth.pth
new file mode 100644
index 00000000..72b006a6
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/import_smth.pth
@@ -0,0 +1 @@
+import smth; smth.extend_path()
\ No newline at end of file
diff --git a/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/relative.egg-link b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/relative.egg-link
new file mode 100644
index 00000000..7a9a6156
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/relative.egg-link
@@ -0,0 +1 @@
+./relative/egg-link/path
diff --git a/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/smth.py b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/smth.py
new file mode 100644
index 00000000..3e3008dd
--- /dev/null
+++ b/test/test_evaluate/sample_venvs/venv34/lib/python3.4/site-packages/smth.py
@@ -0,0 +1,6 @@
+import sys
+sys.path.append('/path/from/smth.py')
+
+
+def extend_path():
+    sys.path.append('/path/from/smth.py:extend_path')
diff --git a/test/test_evaluate/test_imports.py b/test/test_evaluate/test_imports.py
index 52b971ed..0bff5a70 100644
--- a/test/test_evaluate/test_imports.py
+++ b/test/test_evaluate/test_imports.py
@@ -46,11 +46,8 @@ def test_flask_ext(script, name):
     """flask.ext.foo is really imported from flaskext.foo or flask_foo.
     """
     path = os.path.join(os.path.dirname(__file__), 'flask-site-packages')
-    sys.path.append(path)
-    try:
-        assert name in [c.name for c in jedi.Script(script).completions()]
-    finally:
-        sys.path.remove(path)
+    completions = jedi.Script(script, sys_path=[path]).completions()
+    assert name in [c.name for c in completions]
 
 
 @cwd_at('test/test_evaluate/')
@@ -64,3 +61,19 @@ def test_import_unique():
     defs = jedi.Script(src, path='example.py').goto_definitions()
     defs = [d._definition for d in defs]
     assert len(defs) == len(set(defs))
+
+
+def test_cache_works_with_sys_path_param(tmpdir):
+    foo_path = tmpdir.join('foo')
+    bar_path = tmpdir.join('bar')
+    foo_path.join('module.py').write('foo = 123', ensure=True)
+    bar_path.join('module.py').write('bar = 123', ensure=True)
+    foo_completions = jedi.Script('import module; module.',
+                                  sys_path=[foo_path.strpath]).completions()
+    bar_completions = jedi.Script('import module; module.',
+                                  sys_path=[bar_path.strpath]).completions()
+    assert 'foo' in [c.name for c in foo_completions]
+    assert 'bar' not in [c.name for c in foo_completions]
+
+    assert 'bar' in [c.name for c in bar_completions]
+    assert 'foo' not in [c.name for c in bar_completions]
diff --git a/test/test_evaluate/test_namespace_package.py b/test/test_evaluate/test_namespace_package.py
index 213576c8..79993f82 100644
--- a/test/test_evaluate/test_namespace_package.py
+++ b/test/test_evaluate/test_namespace_package.py
@@ -1,55 +1,53 @@
 import jedi
-import sys
 from os.path import dirname, join
 
 
 def test_namespace_package():
-    sys.path.insert(0, join(dirname(__file__), 'namespace_package/ns1'))
-    sys.path.insert(1, join(dirname(__file__), 'namespace_package/ns2'))
-    try:
-        # goto definition
-        assert jedi.Script('from pkg import ns1_file').goto_definitions()
-        assert jedi.Script('from pkg import ns2_file').goto_definitions()
-        assert not jedi.Script('from pkg import ns3_file').goto_definitions()
+    sys_path = [join(dirname(__file__), d)
+                for d in ['namespace_package/ns1', 'namespace_package/ns2']]
 
-        # goto assignment
-        tests = {
-            'from pkg.ns2_folder.nested import foo': 'nested!',
-            'from pkg.ns2_folder import foo': 'ns2_folder!',
-            'from pkg.ns2_file import foo': 'ns2_file!',
-            'from pkg.ns1_folder import foo': 'ns1_folder!',
-            'from pkg.ns1_file import foo': 'ns1_file!',
-            'from pkg import foo': 'ns1!',
-        }
-        for source, solution in tests.items():
-            ass = jedi.Script(source).goto_assignments()
-            assert len(ass) == 1
-            assert ass[0].description == "foo = '%s'" % solution
+    def script_with_path(*args, **kwargs):
+        return jedi.Script(sys_path=sys_path, *args, **kwargs)
 
-        # completion
-        completions = jedi.Script('from pkg import ').completions()
-        names = [str(c.name) for c in completions]  # str because of unicode
-        compare = ['foo', 'ns1_file', 'ns1_folder', 'ns2_folder', 'ns2_file',
-                   'pkg_resources', 'pkgutil', '__name__', '__path__',
-                   '__package__', '__file__', '__doc__']
-        # must at least contain these items, other items are not important
-        assert set(compare) == set(names)
+    # goto definition
+    assert script_with_path('from pkg import ns1_file').goto_definitions()
+    assert script_with_path('from pkg import ns2_file').goto_definitions()
+    assert not script_with_path('from pkg import ns3_file').goto_definitions()
 
-        tests = {
-            'from pkg import ns2_folder as x': 'ns2_folder!',
-            'from pkg import ns2_file as x': 'ns2_file!',
-            'from pkg.ns2_folder import nested as x': 'nested!',
-            'from pkg import ns1_folder as x': 'ns1_folder!',
-            'from pkg import ns1_file as x': 'ns1_file!',
-            'import pkg as x': 'ns1!',
-        }
-        for source, solution in tests.items():
-            for c in jedi.Script(source + '; x.').completions():
-                if c.name == 'foo':
-                    completion = c
-            solution = "statement: foo = '%s'" % solution
-            assert completion.description == solution
+    # goto assignment
+    tests = {
+        'from pkg.ns2_folder.nested import foo': 'nested!',
+        'from pkg.ns2_folder import foo': 'ns2_folder!',
+        'from pkg.ns2_file import foo': 'ns2_file!',
+        'from pkg.ns1_folder import foo': 'ns1_folder!',
+        'from pkg.ns1_file import foo': 'ns1_file!',
+        'from pkg import foo': 'ns1!',
+    }
+    for source, solution in tests.items():
+        ass = script_with_path(source).goto_assignments()
+        assert len(ass) == 1
+        assert ass[0].description == "foo = '%s'" % solution
 
-    finally:
-        sys.path.pop(0)
-        sys.path.pop(0)
+    # completion
+    completions = script_with_path('from pkg import ').completions()
+    names = [str(c.name) for c in completions]  # str because of unicode
+    compare = ['foo', 'ns1_file', 'ns1_folder', 'ns2_folder', 'ns2_file',
+               'pkg_resources', 'pkgutil', '__name__', '__path__',
+               '__package__', '__file__', '__doc__']
+    # must at least contain these items, other items are not important
+    assert set(compare) == set(names)
+
+    tests = {
+        'from pkg import ns2_folder as x': 'ns2_folder!',
+        'from pkg import ns2_file as x': 'ns2_file!',
+        'from pkg.ns2_folder import nested as x': 'nested!',
+        'from pkg import ns1_folder as x': 'ns1_folder!',
+        'from pkg import ns1_file as x': 'ns1_file!',
+        'import pkg as x': 'ns1!',
+    }
+    for source, solution in tests.items():
+        for c in script_with_path(source + '; x.').completions():
+            if c.name == 'foo':
+                completion = c
+        solution = "statement: foo = '%s'" % solution
+        assert completion.description == solution
diff --git a/test/test_evaluate/test_sys_path.py b/test/test_evaluate/test_sys_path.py
index 7691802b..ba1edb25 100644
--- a/test/test_evaluate/test_sys_path.py
+++ b/test/test_evaluate/test_sys_path.py
@@ -1,4 +1,8 @@
 import os
+from glob import glob
+import sys
+
+import pytest
 
 from jedi._compatibility import unicode
 from jedi.parser import Parser, load_grammar
@@ -19,13 +23,37 @@ def test_paths_from_assignment():
     assert paths('sys.path, other = ["a"], 2') == set()
 
 
-def test_get_sys_path(monkeypatch):
-    monkeypatch.setenv('VIRTUAL_ENV', os.path.join(os.path.dirname(__file__),
-                                                   'egg-link', 'venv'))
-    def sitepackages_dir(venv):
-        return os.path.join(venv, 'lib', 'python3.4', 'site-packages')
+# Currently venv site-packages resolution only seeks pythonX.Y/site-packages
+# that belong to the same version as the interpreter to avoid issues with
+# cross-version imports.  "venvs/" dir contains "venv27" and "venv34" that
+# mimic venvs created for py2.7 and py3.4 respectively.  If test runner is
+# invoked with one of those versions, the test below will be run for the
+# matching directory.
+CUR_DIR = os.path.dirname(__file__)
+VENVS = list(glob(
+    os.path.join(CUR_DIR, 'sample_venvs/venv%d%d' % sys.version_info[:2])))
 
-    monkeypatch.setattr('jedi.evaluate.sys_path._get_venv_sitepackages',
-                        sitepackages_dir)
 
-    assert '/path/from/egg-link' in sys_path.get_sys_path()
+@pytest.mark.parametrize('venv', VENVS)
+def test_get_venv_path(venv):
+    pjoin = os.path.join
+    venv_path = sys_path.get_venv_path(venv)
+
+    site_pkgs = (glob(pjoin(venv, 'lib', 'python*', 'site-packages')) +
+                 glob(pjoin(venv, 'lib', 'site-packages')))[0]
+    ETALON = [
+        site_pkgs,
+        pjoin('/path', 'from', 'egg-link'),
+        pjoin(site_pkgs, '.', 'relative', 'egg-link', 'path'),
+        pjoin(site_pkgs, 'dir-from-foo-pth'),
+    ]
+
+    # Ensure that pth and egg-link paths were added.
+    assert venv_path[:len(ETALON)] == ETALON
+
+    # Ensure that none of venv dirs leaked to the interpreter.
+    assert not set(sys.path).intersection(ETALON)
+
+    # Ensure that "import ..." lines were ignored.
+    assert pjoin('/path', 'from', 'smth.py') not in venv_path
+    assert pjoin('/path', 'from', 'smth.py:extend_path') not in venv_path
diff --git a/test/test_parser/test_parser_tree.py b/test/test_parser/test_parser_tree.py
new file mode 100644
index 00000000..480230ba
--- /dev/null
+++ b/test/test_parser/test_parser_tree.py
@@ -0,0 +1,64 @@
+# -*- coding: utf-8    # This file contains Unicode characters.
+
+from textwrap import dedent
+
+import pytest
+
+from jedi._compatibility import u, unicode
+from jedi.parser import Parser, load_grammar
+from jedi.parser import tree as pt
+
+
+class TestsFunctionAndLambdaParsing(object):
+
+    FIXTURES = [
+        ('def my_function(x, y, z):\n    return x + y * z\n', {
+            'name': 'my_function',
+            'call_sig': 'my_function(x, y, z)',
+            'params': ['x', 'y', 'z'],
+        }),
+        ('lambda x, y, z: x + y * z\n', {
+            'name': '<lambda>',
+            'call_sig': '<lambda>(x, y, z)',
+            'params': ['x', 'y', 'z'],
+        }),
+    ]
+
+    @pytest.fixture(params=FIXTURES)
+    def node(self, request):
+        parsed = Parser(load_grammar(), dedent(u(request.param[0])))
+        request.keywords['expected'] = request.param[1]
+        return parsed.module.subscopes[0]
+
+    @pytest.fixture()
+    def expected(self, request, node):
+        return request.keywords['expected']
+    
+    def test_name(self, node, expected):
+        assert isinstance(node.name, pt.Name)
+        assert unicode(node.name) == u(expected['name'])
+    
+    def test_params(self, node, expected):
+        assert isinstance(node.params, list)
+        assert all(isinstance(x, pt.Param) for x in node.params)
+        assert [unicode(x.name) for x in node.params] == [u(x) for x in expected['params']]
+
+    def test_is_generator(self, node, expected):
+        assert node.is_generator() is expected.get('is_generator', False)
+
+    def test_yields(self, node, expected):
+        # TODO: There's a comment in the code noting that the current implementation is incorrect.  This returns an
+        # empty list at the moment (not e.g. False).
+        if expected.get('yields', False):
+            assert node.yields
+        else:
+            assert not node.yields
+
+    def test_annotation(self, node, expected):
+        assert node.annotation() is expected.get('annotation', None)
+
+    def test_get_call_signature(self, node, expected):
+        assert node.get_call_signature() == expected['call_sig']
+
+    def test_doc(self, node, expected):
+        assert node.doc == expected.get('doc') or (expected['call_sig'] + '\n\n')
diff --git a/test/test_regression.py b/test/test_regression.py
index fa81c8af..94132acd 100644
--- a/test/test_regression.py
+++ b/test/test_regression.py
@@ -66,8 +66,9 @@ class TestRegression(TestCase):
         src1 = "def r(a): return a"
         # Other fictional modules in another place in the fs.
         src2 = 'from .. import setup; setup.r(1)'
-        imports.load_module(os.path.abspath(fname), src2)
-        result = Script(src1, path='../setup.py').goto_definitions()
+        script = Script(src1, path='../setup.py')
+        imports.load_module(script._evaluator, os.path.abspath(fname), src2)
+        result = script.goto_definitions()
         assert len(result) == 1
         assert result[0].description == 'class int'