changeset:   77036:11fd82c0e1dd
branch:      venv
parent:      77034:173f8879c54f
user:        Vinay Sajip <vinay_sajip@yahoo.co.uk>
date:        Wed May 16 20:29:56 2012 +0100
files:       Lib/venv/__init__.py
description:
Added --upgrade option to pyvenv.


diff -r 173f8879c54f -r 11fd82c0e1dd Lib/venv/__init__.py
--- a/Lib/venv/__init__.py	Wed May 16 09:50:16 2012 +0100
+++ b/Lib/venv/__init__.py	Wed May 16 20:29:56 2012 +0100
@@ -61,13 +61,15 @@
                   raised.
     :param symlinks: If True, attempt to symlink rather than copy files into
                      virtual environment.
+    :param upgrade: If True, upgrade an existing virtual environment.
     """
 
     def __init__(self, system_site_packages=False, clear=False,
-                 symlinks=False):
+                 symlinks=False, upgrade=False):
         self.system_site_packages = system_site_packages
         self.clear = clear
         self.symlinks = symlinks
+        self.upgrade = upgrade
 
     def create(self, env_dir):
         """
@@ -84,20 +86,26 @@
             raise ValueError(
                 "Symlinking is not supported on OSX framework Python.")
         env_dir = os.path.abspath(env_dir)
-        context = self.create_directories(env_dir)
+        context = self.ensure_directories(env_dir)
         self.create_configuration(context)
         self.setup_python(context)
-        self.setup_scripts(context)
-        self.post_setup(context)
+        if not self.upgrade:
+            self.setup_scripts(context)
+            self.post_setup(context)
 
-    def create_directories(self, env_dir):
+    def ensure_directories(self, env_dir):
         """
         Create the directories for the environment.
 
         Returns a context object which holds paths in the environment,
         for use by subsequent logic.
         """
-        if os.path.exists(env_dir) and not self.clear:
+
+        def create_if_needed(d):
+            if not os.path.exists(d):
+                os.makedirs(d)
+
+        if os.path.exists(env_dir) and not (self.clear or self.upgrade):
             raise ValueError('Directory exists: %s' % env_dir)
         if os.path.exists(env_dir) and self.clear:
             shutil.rmtree(env_dir)
@@ -105,7 +113,7 @@
         context.env_dir = env_dir
         context.env_name = os.path.split(env_dir)[1]
         context.prompt = '(%s) ' % context.env_name
-        os.makedirs(env_dir)
+        create_if_needed(env_dir)
         env = os.environ
         if sys.platform == 'darwin' and '__PYTHONV_LAUNCHER__' in env:
             executable = os.environ['__PYTHONV_LAUNCHER__']
@@ -124,12 +132,12 @@
             incpath = 'include'
             libpath = os.path.join(env_dir, 'lib', 'python%d.%d' % sys.version_info[:2], 'site-packages')
         context.inc_path = path = os.path.join(env_dir, incpath)
-        os.mkdir(path)
-        os.makedirs(libpath)
+        create_if_needed(path)
+        create_if_needed(libpath)
         context.bin_path = binpath = os.path.join(env_dir, binname)
         context.bin_name = binname
         context.env_exe = os.path.join(binpath, exename)
-        os.mkdir(binpath)
+        create_if_needed(binpath)
         return context
 
     def create_configuration(self, context):
@@ -166,7 +174,8 @@
         force_copy = not self.symlinks
         if not force_copy:
             try:
-                os.symlink(src, dst)
+                if not os.path.islink(dst): # can't link to itself!
+                    os.symlink(src, dst)
             except Exception:   # may need to use a more specific exception
                 logger.warning('Unable to symlink %r to %r', src, dst)
                 force_copy = True
@@ -374,8 +383,10 @@
         from threading import Thread
         from urllib.request import urlretrieve
 
-        # This is a placeholder URL - there are stale-data problems with
-        # the BitBucket CDN
+        # This version of distribute_setup.py fetches a
+        # venv-aware version of distribute
+        # This class won't be checked into Python, anyway,
+        # so it's just for exploring venvs
         url = 'http://www.red-dove.com/distribute_setup.py'
         binpath = context.bin_path
         distpath = os.path.join(binpath, 'distribute_setup.py')
@@ -453,7 +464,12 @@
                             action='store_true', dest='system_site',
                             help="Give the virtual environment access to the "
                                  "system site-packages dir. ")
-        parser.add_argument('--symlinks', default=False,
+        if os.name == 'nt' or (sys.platform == 'darwin' and
+                               'Library/Framework' in sys.base_prefix):
+            use_symlinks = False
+        else:
+            use_symlinks = True
+        parser.add_argument('--symlinks', default=use_symlinks,
                             action='store_true', dest='symlinks',
                             help="Attempt to symlink rather than copy.")
         parser.add_argument('--clear', default=False, action='store_true',
@@ -462,11 +478,19 @@
                                                'exists. If not specified and '
                                                'the directory exists, an error'
                                                ' is raised.')
+        parser.add_argument('--upgrade', default=False, action='store_true',
+                            dest='upgrade', help='Upgrade the environment '
+                                               'directory to use this version '
+                                               'of Python, assuming it has been '
+                                               'upgraded in-place.')
         options = parser.parse_args(args)
+        if options.upgrade and options.clear:
+            raise ValueError('you cannot supply --upgrade and --clear together.')
         # XXX This will be changed to EnvBuilder
         builder = DistributeEnvBuilder(system_site_packages=options.system_site,
                                        clear=options.clear,
                                        symlinks=options.symlinks,
+                                       upgrade=options.upgrade,
                                        nodist=options.nodist)
         for d in options.dirs:
             builder.create(d)