Hackable mercurial based on python 2.7

[Adrian Buehlmann]

On 2012-06-25 09:04, Angel Ezquerra wrote:
> On Mon, Jun 25, 2012 at 8:55 AM, Adrian Buehlmann <adrian at cadifra.com> wrote:
>> On 2012-06-25 07:50, Angel Ezquerra wrote:
>>> On Mon, Jun 25, 2012 at 12:59 AM, Adrian Buehlmann <adrian at cadifra.com> wrote:
>>>> On 2012-06-19 08:16, Angel Ezquerra wrote:
>>>>> Matt,
>>>>>
>>>>> Steve has just released the first TortoiseHg and mercurial installer
>>>>> nightly builds which are based on Python 2.7. I believe the plan is to
>>>>> only release 2.7 builds from now on (Steve, please correct me if I'm
>>>>> wrong).
>>>>>
>>>>> I wonder, do you have any plans to move the hackable mercurial package
>>>>> to 2.7 as well?
>>>>
>>>> Angel, do you have x64 Windows?
>>>>
>>>> I've just uploaded
>>>>
>>>>  hg-hackable-x64-python27-ec5ef276077f-1.7z
>>>>
>>>> to https://bitbucket.org/abuehl/downloads/downloads
>>>>
>>>> It includes my latest hg.exe.
>>>>
>>>> It does not include Python, so you need to install that separately
>>>> (requires Python 2.7).
>>>
>>> Adrian,
>>>
>>> I guess this needs the x64 version of Python 2.7?
>>
>> Yes, it requires a x64 Python installed.
>>
>> I use the official
>> http://www.python.org/ftp/python/2.7.3/python-2.7.3.amd64.msi
>>
>> $ python
>> Python 2.7.3 (default, Apr 10 2012, 23:24:47) [MSC v.1500 64 bit
>> (AMD64)] on win32
>> Type "help", "copyright", "credits" or "license" for more information.
>>>>>
>>
>> Install it "for all users of this computer", if you can (that is, if you
>> have admin rights on that computer, which I bet you have, since
>> installing TortoiseHg requires admin rights too for installing. [And no,
>> I won't help changing that for those whining about it each time I
>> mention it]).
>>
>> Running python-2.7.3.amd64.msi also won't change the PATH. I recommend
>> you let install it into C:\python27_x64 or something similar (I forgot
>> what the default is, that the installer proposes. It may already be
>> that). Double-click python-2.7.3.amd64.msi to start the installation and
>> then go through the dialogs (accept the UAC admin prompt). It's a
>> familiar msi installer, like the one of TortoiseHg.
>>
>> It will install python27.dll in C:\Windows\system32 if you let install
>> it "for all users of this computer" (I think that's the default), so it
>> can be easily found by every program that links to it (like my hg.exe).
>>
>> AMD64 is just the 64-bit processor architecture, it doesn't require an
>> AMD CPU. Intel will do fine (in the past, there was also another 64-bit
>> architecture, IA64).
>>
>>> I'm on 64 bit windows 7,
>>
>> Nice. So you have AMD64 architecture hardware (like many people do
>> today). Start using it! :-)
>>
>>> and I have python 2.7 installer, but it is a x32 version
>>> (actually it is the Enthough's Distribution Python 2.7 version). When
>>> I run your hg.exe I get:
>>>
>>> ImportError: No module named site
>>
>> See above.
>>
> 
> I'm using a 32 bit python on a 64 bit OS because some important python
> packages do not work for 64 bit Python yet. Particularly, I don't
> think there are official packages for numpy, scipy and matplotlib,
> which I use.
> 
> Anyway, I'll give this a try, but I will probably need to go back to
> 32 bit python afterwards.

No, you don't have to. I think you haven't understood the situation.

You can use multiple Python's in parallel, which includes x64 and x86
versions. It's rather unlikely that istalling python-2.7.3.amd64.msi
will affect your existing python setup. It won't even touch your PATH
environment variable. If you want entering "python" in a shell to start
the CPython x64 python, you'd have to change your PATH yourself.

I have here (from a chat with cmd.exe):

  $ cd
  C:\

  $ dir Python*
   Volume in drive C has no label.
   Volume Serial Number is F80E-0A52

   Directory of C:\

  24.06.2012  22:57    <SYMLINKD>     Python [C:\Python27_x64]
  26.05.2012  12:08    <DIR>          Python26_x64
  26.05.2012  12:08    <DIR>          Python26_x86
  16.06.2012  13:12    <DIR>          Python27_x64
  16.06.2012  13:12    <DIR>          Python27_x86
                 0 File(s)              0 bytes
                 5 Dir(s)  377'188'397'056 bytes free

So I have 4 Pythons installed. The symlink currently points to
C:\Python27_x64, but that's mostly because I have C:\Python in my PATH
and I would like to have exactly one "python" in PATH at a time. But I
can also start the python interpreter with, let's say
C:\Python26_x86\python.exe.

These four Pythons all live happily together. The x64 versions install
python26.dll and python27.dll in C:\Windows\system32, the x86 versions
install python26.dll and python27.dll in C:\Windows\SysWOW64.

The 32-bit and the 64-bit world are perfecty seperated on your Windows 7
x74. You won't even notice it.

If a 32-bit process tries to look after a dll in C:\Windows\system32,
Windows 7 x64 will automatically redirect the file access to
C:\Windows\SysWOW64, the process won't even notice it.

There are other mechanisms like that in place. E.g. similar things
happen with the registry.