Changeset 391 for python/trunk/Doc/using/windows.rst

Timestamp:

Mar 19, 2014, 11:31:01 PM (11 years ago)

Author:

dmik

Message:

python: Merge vendor 2.7.6 to trunk.

Location:

python/trunk

Files:

• . (modified) (1 prop)
• Doc/using/windows.rst (modified) (4 diffs)

python/trunk/Doc/using/windows.rst

@@ -48 +48 @@
       by Richard Dooling, 2006
 
-   `Installing on Windows <http://diveintopython.org/installing_python/windows.html>`_
+   `Installing on Windows <http://diveintopython.net/installing_python/windows.html>`_
       in "`Dive into Python: Python from novice to pro
-      <http://diveintopython.org/index.html>`_"
+      <http://diveintopython.net/index.html>`_"
       by Mark Pilgrim, 2004,
       ISBN 1-59059-356-1
@@ -84 +84 @@
 settings in Windows.
 
+
+.. _setting-envvars:
 
 Excursus: Setting environment variables
@@ -159 +161 @@
 :file:`C:\\Python\\Lib\\site-packages\\`.
 
-.. `` this fixes syntax highlighting errors in some editors due to the \\ hackery
-
-You can add folders to your search path to make Python's import mechanism search
-in these directories as well.  Use :envvar:`PYTHONPATH`, as described in
-:ref:`using-on-envvars`, to modify :data:`sys.path`.  On Windows, paths are
-separated by semicolons, though, to distinguish them from drive identifiers
-(:file:`C:\\` etc.).
-
-.. ``
-
-Modifying the module search path can also be done through the Windows registry:
-Edit
-:file:`HKEY_LOCAL_MACHINE\\SOFTWARE\\Python\\PythonCore\\{version}\\PythonPath\\`,
-as described above for the environment variable :envvar:`%PYTHONPATH%`.  A
-convenient registry editor is :program:`regedit` (start it by typing "regedit"
-into :menuselection:`Start --> Run`).
+This is how :data:`sys.path` is populated on Windows:
+
+* An empty entry is added at the start, which corresponds to the current
+  directory.
+
+* If the environment variable :envvar:`PYTHONPATH` exists, as described in
+  :ref:`using-on-envvars`, its entries are added next.  Note that on Windows,
+  paths in this variable must be separated by semicolons, to distinguish them
+  from the colon used in drive identifiers (``C:\`` etc.).
+
+* Additional "application paths" can be added in the registry as subkeys of
+  :samp:`\\SOFTWARE\\Python\\PythonCore\\{version}\\PythonPath` under both the
+  ``HKEY_CURRENT_USER`` and ``HKEY_LOCAL_MACHINE`` hives.  Subkeys which have
+  semicolon-delimited path strings as their default value will cause each path
+  to be added to :data:`sys.path`.  (Note that all known installers only use
+  HKLM, so HKCU is typically empty.)
+
+* If the environment variable :envvar:`PYTHONHOME` is set, it is assumed as
+  "Python Home".  Otherwise, the path of the main Python executable is used to
+  locate a "landmark file" (``Lib\os.py``) to deduce the "Python Home".  If a
+  Python home is found, the relevant sub-directories added to :data:`sys.path`
+  (``Lib``, ``plat-win``, etc) are based on that folder.  Otherwise, the core
+  Python path is constructed from the PythonPath stored in the registry.
+
+* If the Python Home cannot be located, no :envvar:`PYTHONPATH` is specified in
+  the environment, and no registry entries can be found, a default path with
+  relative entries is used (e.g. ``.\Lib;.\plat-win``, etc).
+
+The end result of all this is:
+
+* When running :file:`python.exe`, or any other .exe in the main Python
+  directory (either an installed version, or directly from the PCbuild
+  directory), the core path is deduced, and the core paths in the registry are
+  ignored.  Other "application paths" in the registry are always read.
+
+* When Python is hosted in another .exe (different directory, embedded via COM,
+  etc), the "Python Home" will not be deduced, so the core path from the
+  registry is used.  Other "application paths" in the registry are always read.
+
+* If Python can't find its home and there is no registry (eg, frozen .exe, some
+  very strange installation setup) you get a path with some default, but
+  relative, paths.
 
 
@@ -267 +295 @@
 `source <http://python.org/download/source/>`_. You can download either the
 latest release's source or just grab a fresh `checkout
-<http://www.python.org/dev/faq/#how-do-i-get-a-checkout-of-the-repository-read-only-and-read-write>`_.
+<http://docs.python.org/devguide/setup#checking-out-the-code>`_.
 
 For Microsoft Visual C++, which is the compiler with which official Python