source: install/bootstrap.py @ 1112

#!/usr/bin/env python
import os, stat, sys, platform, subprocess
home = 'https://subversion.xor.aps.anl.gov/pyGSAS/'
print 70*'*'
print 'Checking python packages...',
missing = []
for pkg in ['numpy','scipy','matplotlib','wx']:
    try:
        exec('import '+pkg)
    except:
        missing.append(pkg)

if missing:
    print """Sorry, this version of Python cannot be used
for GSAS-II. It is missing the following package(s):
\t""",
    for pkg in missing: print " ",pkg,
    print 
    print "We suggest installing the Canopy Express package (must be 32 bit for Mac) at\nhttp://www.enthought.com/store"
    sys.exit()

gsaspath = os.path.split(sys.argv[0])[0]
gsaspath = os.path.abspath(os.path.expanduser(gsaspath))

print 'Checking for subversion...',
# add the standard location for wandisco svn to the path
for path in os.environ['PATH'].split(':')+['/opt/subversion/bin',]:
    svn = os.path.join(path,'svn')
    try:
        p = subprocess.Popen([svn,'help'],stdout=subprocess.PIPE)
        res = p.stdout.read()
        p.communicate()
        break
    except:
        pass
else:
    raise Exception('Subversion (svn) not found')
print ' found in',svn
print 'OK'

print 'GSAS-II is being bootstrapped from repository\n\t',home,'\nto '+gsaspath

print 'Determining system type...',
if sys.platform.startswith('linux'):
    #if platform.processor().find('86') <= -1:
    #    ans = raw_input("Note, GSAS requires an Intel-compatible processor and 32-bit"
    #                    "libraries.\nAre you sure want to continue? [Yes]/no: ")
    #    if ans.lower().find('no') > -1: sys.exit()
    repos = 'linux'
    print 'Linux, assuming Intel-compatible'
elif sys.platform == "darwin" and platform.processor() == 'i386':
    repos = 'osxi86'
    print 'Mac OS X, Intel-compatible'
elif sys.platform == "darwin":
    repos = 'osxppc'
    print 'Mac OS X, PowerPC -- you will need to run scons on fsource files'
else:
    print 'Unidentifed platform -- you may need to run scons on fsource files'

cmds = (
    ([svn, 'co', home+ 'trunk/', gsaspath],'loading GSAS-II'),
)

for cmd,msg in cmds: 
    print 70*'*'
    print msg + ' from ' + cmd[2]
    for item in cmd: print item,
    print ""
    p = subprocess.call(cmd)

#===========================================================================
# could try to load .so files here and run scons if needed.

#===========================================================================
# on a Mac, make an applescript 
if sys.platform.startswith('darwin') and os.path.exists(
    os.path.join(gsaspath,"makeMacApp.py")):
    execfile(os.path.join(gsaspath,"makeMacApp.py"))
#===========================================================================
# On linux, make desktop icon
if sys.platform.startswith('linux'):
    desktop_template = """
[Desktop Entry]
Encoding=UTF-8
Version=1.0
Type=Application
Terminal=false
Exec=xterm -hold -e %s
Name=GSAS-II
Icon=%s
"""
    loc = '~/Desktop/'
    eloc = os.path.expanduser(loc)
    dfile = os.path.join(eloc,'GSASII.desktop')
    icon = os.path.join(gsaspath, 'gsas2.png')
    script = os.path.join(gsaspath, 'GSASII.py')
    os.chmod(script, # make the .py file executable and readable
             stat.S_IXUSR | stat.S_IRUSR | stat.S_IRGRP | stat.S_IXGRP | stat.S_IXOTH)
    if os.path.exists(eloc):
        open(dfile,'w').write(desktop_template % (script,icon))
        os.chmod(
            dfile,
            stat.S_IWUSR | stat.S_IXUSR | stat.S_IRUSR | stat.S_IRGRP | stat.S_IXGRP | stat.S_IXOTH)
        print("created GNOME desktop shortcut "+dfile)