Controlling which Python to use
-------------------------------
The following assumes that you have Python 2.4 installed.
We can specify the python to use by specifying the name of a section
to read the Python executable from. The default is the section
defined by the python buildout option.
We have a link server:
>>> print get(link_server),
bigdemo-0.1-py2.4.egg
demo-0.1-py2.4.egg
demo-0.2-py2.4.egg
demo-0.3-py2.4.egg
demo-0.4c1-py2.4.egg
demoneeded-1.0.zip
demoneeded-1.1.zip
demoneeded-1.2c1.zip
extdemo-1.4.zip
index/
other-1.0-py2.4.egg
We have a sample buildout. Let's update its configuration file to
install the demo package using Python 2.4.
>>> write(sample_buildout, 'buildout.cfg',
... """
... [buildout]
... parts = demo
... eggs-directory = eggs
... index = http://www.python.org/pypi/
...
... [python2.4]
... executable = %(python24)s
...
... [demo]
... recipe = zc.recipe.egg
... eggs = demo <0.3
... find-links = %(server)s
... python = python2.4
... interpreter = py-demo
... """ % dict(server=link_server, python24=other_executable))
Now, if we run the buildout:
>>> import os
>>> os.chdir(sample_buildout)
>>> buildout = os.path.join(sample_buildout, 'bin', 'buildout')
>>> print system(buildout),
Installing demo.
Getting distribution for 'demo<0.3'.
Got demo 0.2.
Getting distribution for 'demoneeded'.
Got demoneeded 1.2c1.
Generated script '/sample-buildout/bin/demo'.
Generated interpreter '/sample-buildout/bin/py-demo'.
we'll get the Python 2.4 eggs for demo and demoneeded:
>>> ls(sample_buildout, 'eggs')
- demo-0.2-py2.4.egg
- demoneeded-1.2c1-py2.4.egg
d setuptools-0.6-py2.5.egg
- zc.buildout-1.0-py2.5.egg
And the generated scripts invoke Python 2.4:
>>> import sys
>>> if sys.platform == 'win32':
... script_name = 'demo-script.py'
... else:
... script_name = 'demo'
>>> f = open(os.path.join(sample_buildout, 'bin', script_name))
>>> shebang = f.readline().strip()
>>> if shebang[:3] == '#!"' and shebang[-1] == '"':
... shebang = '#!'+shebang[3:-1]
>>> shebang == '#!' + other_executable
True
>>> print f.read(), # doctest: +NORMALIZE_WHITESPACE
import sys
sys.path[0:0] = [
'/sample-buildout/eggs/demo-0.2-py2.4.egg',
'/sample-buildout/eggs/demoneeded-1.2c1-py2.4.egg',
]
import eggrecipedemo
if __name__ == '__main__':
eggrecipedemo.main()
>>> if sys.platform == 'win32':
... f = open(os.path.join(sample_buildout, 'bin', 'py-demo-script.py'))
... else:
... f = open(os.path.join(sample_buildout, 'bin', 'py-demo'))
>>> shebang = f.readline().strip()
>>> if shebang[:3] == '#!"' and shebang[-1] == '"':
... shebang = '#!'+shebang[3:-1]
>>> shebang == '#!' + other_executable
True
>>> print f.read(), # doctest: +NORMALIZE_WHITESPACE
import sys
sys.path[0:0] = [
'/sample-buildout/eggs/demo-0.2-py2.4.egg',
'/sample-buildout/eggs/demoneeded-1.2c1-py2.4.egg',
]
_interactive = True
if len(sys.argv) > 1:
_options, _args = __import__("getopt").getopt(sys.argv[1:], 'ic:m:')
_interactive = False
for (_opt, _val) in _options:
if _opt == '-i':
_interactive = True
elif _opt == '-c':
exec _val
elif _opt == '-m':
sys.argv[1:] = _args
_args = []
__import__("runpy").run_module(
_val, {}, "__main__", alter_sys=True)
if _args:
sys.argv[:] = _args
__file__ = _args[0]
del _options, _args
execfile(__file__)
if _interactive:
del _interactive
__import__("code").interact(banner="", local=globals())
>>> f.close()