_system_path.py 文件源码

def get_previous_install_prefixes(pyversion, arch, allusers=True):
    """Returns a list of prefixes for all old installations of this arch so that
       they can be removed from PATH if present. Note, it would be preferable to
       uninstall them properly instead.
    """
    if allusers:
        # All Users
        key, subkey = (reg.HKEY_LOCAL_MACHINE, r'SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\')
    else:
        # Just Me
        key, subkey = (reg.HKEY_CURRENT_USER, r'SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\')

    keylist = []
    # We ignore pyversion and instead look for any *conda installations.
    regex = re.compile('Python \S+ \(\S+conda[0-9]+ \S+ '+arch+'\)')
    _reg_query_sub_keys(key, subkey, keylist)
    results = []
    for uninstsubkey in keylist:
        final_part = os.path.basename(uninstsubkey.rstrip('\\'))
        if regex.match(final_part):
            try:
                with reg.OpenKeyEx(key, uninstsubkey, 0,
                                 reg.KEY_QUERY_VALUE) as keyhandle:
                    reg_value = reg.QueryValueEx(keyhandle, 'UninstallString')
                    results.append(os.path.dirname(re.sub(r'^"|"$', '', reg_value[0])))
            except:
                pass
    return results