403Webshell
Server IP : 103.119.228.120  /  Your IP : 18.220.242.160
Web Server : Apache
System : Linux v8.techscape8.com 3.10.0-1160.119.1.el7.tuxcare.els2.x86_64 #1 SMP Mon Jul 15 12:09:18 UTC 2024 x86_64
User : nobody ( 99)
PHP Version : 5.6.40
Disable Function : shell_exec,symlink,system,exec,proc_get_status,proc_nice,proc_terminate,define_syslog_variables,syslog,openlog,closelog,escapeshellcmd,passthru,ocinum cols,ini_alter,leak,listen,chgrp,apache_note,apache_setenv,debugger_on,debugger_off,ftp_exec,dl,dll,myshellexec,proc_open,socket_bind,proc_close,escapeshellarg,parse_ini_filepopen,fpassthru,exec,passthru,escapeshellarg,escapeshellcmd,proc_close,proc_open,ini_alter,popen,show_source,proc_nice,proc_terminate,proc_get_status,proc_close,pfsockopen,leak,apache_child_terminate,posix_kill,posix_mkfifo,posix_setpgid,posix_setsid,posix_setuid,dl,symlink,shell_exec,system,dl,passthru,escapeshellarg,escapeshellcmd,myshellexec,c99_buff_prepare,c99_sess_put,fpassthru,getdisfunc,fx29exec,fx29exec2,is_windows,disp_freespace,fx29sh_getupdate,fx29_buff_prepare,fx29_sess_put,fx29shexit,fx29fsearch,fx29ftpbrutecheck,fx29sh_tools,fx29sh_about,milw0rm,imagez,sh_name,myshellexec,checkproxyhost,dosyayicek,c99_buff_prepare,c99_sess_put,c99getsource,c99sh_getupdate,c99fsearch,c99shexit,view_perms,posix_getpwuid,posix_getgrgid,posix_kill,parse_perms,parsesort,view_perms_color,set_encoder_input,ls_setcheckboxall,ls_reverse_all,rsg_read,rsg_glob,selfURL,dispsecinfo,unix2DosTime,addFile,system,get_users,view_size,DirFiles,DirFilesWide,DirPrintHTMLHeaders,GetFilesTotal,GetTitles,GetTimeTotal,GetMatchesCount,GetFileMatchesCount,GetResultFiles,fs_copy_dir,fs_copy_obj,fs_move_dir,fs_move_obj,fs_rmdir,SearchText,getmicrotime
MySQL : ON |  cURL : ON |  WGET : ON |  Perl : ON |  Python : ON |  Sudo : ON |  Pkexec : ON
Directory :  /lib64/python2.7/Demo/metaclasses/

Upload File :
current_dir [ Writeable] document_root [ Writeable]

 

Command :


[ Back ]     

Current File : /lib64/python2.7/Demo/metaclasses/Eiffel.py
"""Support Eiffel-style preconditions and postconditions.

For example,

class C:
    def m1(self, arg):
        require arg > 0
        return whatever
        ensure Result > arg

can be written (clumsily, I agree) as:

class C(Eiffel):
    def m1(self, arg):
        return whatever
    def m1_pre(self, arg):
        assert arg > 0
    def m1_post(self, Result, arg):
        assert Result > arg

Pre- and post-conditions for a method, being implemented as methods
themselves, are inherited independently from the method.  This gives
much of the same effect of Eiffel, where pre- and post-conditions are
inherited when a method is overridden by a derived class.  However,
when a derived class in Python needs to extend a pre- or
post-condition, it must manually merge the base class' pre- or
post-condition with that defined in the derived class', for example:

class D(C):
    def m1(self, arg):
        return arg**2
    def m1_post(self, Result, arg):
        C.m1_post(self, Result, arg)
        assert Result < 100

This gives derived classes more freedom but also more responsibility
than in Eiffel, where the compiler automatically takes care of this.

In Eiffel, pre-conditions combine using contravariance, meaning a
derived class can only make a pre-condition weaker; in Python, this is
up to the derived class.  For example, a derived class that takes away
the requirement that arg > 0 could write:

    def m1_pre(self, arg):
        pass

but one could equally write a derived class that makes a stronger
requirement:

    def m1_pre(self, arg):
        require arg > 50

It would be easy to modify the classes shown here so that pre- and
post-conditions can be disabled (separately, on a per-class basis).

A different design would have the pre- or post-condition testing
functions return true for success and false for failure.  This would
make it possible to implement automatic combination of inherited
and new pre-/post-conditions.  All this is left as an exercise to the
reader.

"""

from Meta import MetaClass, MetaHelper, MetaMethodWrapper

class EiffelMethodWrapper(MetaMethodWrapper):

    def __init__(self, func, inst):
        MetaMethodWrapper.__init__(self, func, inst)
        # Note that the following causes recursive wrappers around
        # the pre-/post-condition testing methods.  These are harmless
        # but inefficient; to avoid them, the lookup must be done
        # using the class.
        try:
            self.pre = getattr(inst, self.__name__ + "_pre")
        except AttributeError:
            self.pre = None
        try:
            self.post = getattr(inst, self.__name__ + "_post")
        except AttributeError:
            self.post = None

    def __call__(self, *args, **kw):
        if self.pre:
            apply(self.pre, args, kw)
        Result = apply(self.func, (self.inst,) + args, kw)
        if self.post:
            apply(self.post, (Result,) + args, kw)
        return Result

class EiffelHelper(MetaHelper):
    __methodwrapper__ = EiffelMethodWrapper

class EiffelMetaClass(MetaClass):
    __helper__ = EiffelHelper

Eiffel = EiffelMetaClass('Eiffel', (), {})


def _test():
    class C(Eiffel):
        def m1(self, arg):
            return arg+1
        def m1_pre(self, arg):
            assert arg > 0, "precondition for m1 failed"
        def m1_post(self, Result, arg):
            assert Result > arg
    x = C()
    x.m1(12)
##    x.m1(-1)

if __name__ == '__main__':
    _test()

Youez - 2016 - github.com/yon3zu
LinuXploit