Re: Python end of file marker similar to perl's __END__
Neil Cerutti wrote: On 2007-08-01, Cameron Laird [EMAIL PROTECTED] wrote: . I want to re-emphasize the triple-quote it tip mentioned earlier in this thread. I think the original questioner will find this quite satisfying, if I understand his situ- ation at all. *I* certainly have source code with embedded junk commented out as multi-line strings. I used to do that, but now that I use doctests so much it's infeasible to comment out arbitrary code that way, since they can't necessarily nest. If you consistently use e.g. ''' for doc strings, you can use to comment out code blocks. I still think it's better to do test-driven programming though. Then you will very rarely have large blocks on non-working code. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On Thu, 02 Aug 2007 10:00:04 +1000, Ben Finney wrote: beginner [EMAIL PROTECTED] writes: Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. I think the unaddressed question is: Why is there so much code in your module with invalid syntax that this trick would be useful? It's not just bad syntax that makes the triple-quote or comment trick useful. Sometimes you're experimenting, or perhaps tinkering is a better description. Your aim isn't to end up with a working piece of code, but to learn something (e.g. how do decorators work?). You may end up with working code at the end, but the finished code isn't the aim of the exercise and may not be kept. Because you're experimenting, you might end up with ten different versions of a function, and not all of them will compile, let alone execute correctly. It's handy to be able to comment them out and reload() the file, and while some editors will do bulk comment/uncomment of text, the triple-quoted string trick is easy enough that you can use it in Microsoft's Notepad. That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. I would strongly recommend you examine what part of your practice is leading you to write so much code with invalid syntax, without immediately testing and fixing it. Eliminate that part of the process -- possibly with test-driven development. While the discipline of TDD is good and useful, there's a time and place for unstructured and informal experimentation too. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On 2007-08-02, Magnus Lycka [EMAIL PROTECTED] wrote: Neil Cerutti wrote: On 2007-08-01, Cameron Laird [EMAIL PROTECTED] wrote: . I want to re-emphasize the triple-quote it tip mentioned earlier in this thread. I think the original questioner will find this quite satisfying, if I understand his situ- ation at all. *I* certainly have source code with embedded junk commented out as multi-line strings. I used to do that, but now that I use doctests so much it's infeasible to comment out arbitrary code that way, since they can't necessarily nest. If you consistently use e.g. ''' for doc strings, you can use to comment out code blocks. But then I couldn't use in my docstrings! ;) Actually, I wound up converting all my multiline doctests to use concatenation instead, since they were ruining my syntax highlighting performance in Vim. -- Neil Cerutti We shall reach greater and greater platitudes of achievement. --Richard J. Daley -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On Aug 2, 8:08 am, Neil Cerutti [EMAIL PROTECTED] wrote: On 2007-08-02, Magnus Lycka [EMAIL PROTECTED] wrote: Neil Cerutti wrote: On 2007-08-01, Cameron Laird [EMAIL PROTECTED] wrote: . I want to re-emphasize the triple-quote it tip mentioned earlier in this thread. I think the original questioner will find this quite satisfying, if I understand his situ- ation at all. *I* certainly have source code with embedded junk commented out as multi-line strings. I used to do that, but now that I use doctests so much it's infeasible to comment out arbitrary code that way, since they can't necessarily nest. If you consistently use e.g. ''' for doc strings, you can use to comment out code blocks. But then I couldn't use in my docstrings! ;) Actually, I wound up converting all my multiline doctests to use concatenation instead, since they were ruining my syntax highlighting performance in Vim. -- Neil Cerutti We shall reach greater and greater platitudes of achievement. --Richard J. Daley Python comes with an IDE that can do bulk commenting or uncommenting. It's IDLE. Just select the test to comment out and press ALT+3. To uncomment, press ALT+4. It's cool! Mike -- http://mail.python.org/mailman/listinfo/python-list
Experimentation and dealing with transient broken code (was: Python end of file marker similar to perl's __END__)
Steven D'Aprano [EMAIL PROTECTED] writes: It's not just bad syntax that makes the triple-quote or comment trick useful. Okay. That was the original reason given for refusing suggestions like return early from the function etc. I answered in that context. Because you're experimenting, you might end up with ten different versions of a function, and not all of them will compile, let alone execute correctly. If a function doesn't compile, I don't understand why you're not either throwing it away or fixing it. As for multiple versions? That's what version control is for. With client-only, distributed VCSes like Bazaar and Mercurial (both written in Python) you don't even have to do anything other than install the software to begin using it. There's no reason not to be using a version control system any time you're coding — even (especially!) while just experimenting. It's handy to be able to comment them out and reload() the file Why not simply fix them and reload() instead? Why keep something inside the module that doesn't work, and indeed has just been proven not to work? (If the only reason is because I might need it later, again, that's what a VCS is for.) -- \I'd take the awe of understanding over the awe of ignorance | `\ any day. -- Douglas Adams | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On Wed, 01 Aug 2007 05:44:21 +, Michele Simionato wrote: On Aug 1, 5:53 am, beginner [EMAIL PROTECTED] wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? I wished from something like that. What you can do at the moment, is to comment or triple quote the code you don't want to run. Or, if in a function body, you could insert a `return` statement. When in top-level code, invoking `sys.exit` (or exit/quit) can do the trick. A ``raise Exception`` might help, too, but could be kinda distracting sometimes. So, there is no general purpose solution as perl has it (I guess that __END__ works everywhere at least), rather different solutions for different cases. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
beginner [EMAIL PROTECTED] writes: In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. IIRC, this Perl feature is specifically intended to work with its feature of reading data from the same file, as all the lines following that marker. This is very handy when testing my program. If my understanding above is correct, then your use of it is a happy repurposing of the feature, and not an intended use. Does python have something similar? Since it doesn't have the behaviour that inspired that feature in Perl, I doubt it. -- \ Everything is futile. -- Marvin of Borg | `\ | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
Stargaming wrote: On Wed, 01 Aug 2007 05:44:21 +, Michele Simionato wrote: On Aug 1, 5:53 am, beginner [EMAIL PROTECTED] wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? I wished from something like that. What you can do at the moment, is to comment or triple quote the code you don't want to run. Or, if in a function body, you could insert a `return` statement. When in top-level code, invoking `sys.exit` (or exit/quit) can do the trick. A ``raise Exception`` might help, too, but could be kinda distracting sometimes. So, there is no general purpose solution as perl has it (I guess that __END__ works everywhere at least), rather different solutions for different cases. I think you have missed the point. A return statement or call to sys.exit() doesn't remove the requirement that the rest ofthe source file be legal Python. In a Perl program you can put anything you like after __END__. regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden --- Asciimercial -- Get on the web: Blog, lens and tag the Internet Many services currently offer free registration --- Thank You for Reading - -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On Wed, 01 Aug 2007 06:56:36 -0400, Steve Holden wrote: Stargaming wrote: On Wed, 01 Aug 2007 05:44:21 +, Michele Simionato wrote: On Aug 1, 5:53 am, beginner [EMAIL PROTECTED] wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? I wished from something like that. What you can do at the moment, is to comment or triple quote the code you don't want to run. Or, if in a function body, you could insert a `return` statement. When in top-level code, invoking `sys.exit` (or exit/quit) can do the trick. A ``raise Exception`` might help, too, but could be kinda distracting sometimes. So, there is no general purpose solution as perl has it (I guess that __END__ works everywhere at least), rather different solutions for different cases. I think you have missed the point. A return statement or call to sys.exit() doesn't remove the requirement that the rest ofthe source file be legal Python. In a Perl program you can put anything you like after __END__. regards Steve That was my point actually. No, there is no such general purpose solution as in perl, but if he just wanted to quit execution (to, eg., not commit changes to his database), this would be the way to go. Multiline strings are the other way to include (nearly) arbitrary data. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
beginner wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? raise SystemExit() exits the program at that point (unless you catch the exception...) import sys;sys.exit(0) is basically another spelling of the same thing. It doesn't mean that the interpreter ignores the rest of the file though, so it will complain about syntax in the whole file. Since I don't usually write linear top-to-bottom scripts in Python, I don't really see the use of splitting a file in an interpreted top and an ignored bottom though. I'd suggest employing a test driven approach to development. Then you don't usually have big chunks of code that you don't want to run. All that's there works (almost)... See e.g. http://powertwenty.com/kpd/downloads/TestDrivenDevelopmentInPython.pdf -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On Jul 31, 10:53 pm, beginner [EMAIL PROTECTED] wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? Thanks, Geoffrey Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On 2007-08-01, beginner [EMAIL PROTECTED] wrote: Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. A C-like trick might be helpful while refactoring: working code if False: non-working code You have to indent all the non-working code by one level, but with a good editor that's a snap. Python will still parse the following lines (it must be valid Python syntax), but the resulting parse tree won't be executed. -- Neil Cerutti -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
beginner wrote: On Jul 31, 10:53 pm, beginner [EMAIL PROTECTED] wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? Thanks, Geoffrey Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. In emacs, I simply mark that portion of code and do M-x comment-region That's it. And I don't think a language should support things __END__ - commenting is enough. It's unfortunate that Python doesn't support multi-line-comments though. But as I said, that my Editor can handle for me. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On 8/1/07, beginner [EMAIL PROTECTED] wrote: On Jul 31, 10:53 pm, beginner [EMAIL PROTECTED] wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? Thanks, Geoffrey Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. You'll probably find greater gains by embracing the limitation and using it to help you refactor your code into smaller, more discrete modules. Many of pythons limitations that beginners complain about are of this nature. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
In article [EMAIL PROTECTED], Neil Cerutti [EMAIL PROTECTED] wrote: On 2007-08-01, beginner [EMAIL PROTECTED] wrote: Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. A C-like trick might be helpful while refactoring: working code if False: non-working code You have to indent all the non-working code by one level, but with a good editor that's a snap. Python will still parse the following lines (it must be valid Python syntax), but the resulting parse tree won't be executed. . . . I want to re-emphasize the triple-quote it tip mentioned earlier in this thread. I think the original questioner will find this quite satisfying, if I understand his situ- ation at all. *I* certainly have source code with embedded junk commented out as multi-line strings. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On 2007-08-01, Cameron Laird [EMAIL PROTECTED] wrote: In article [EMAIL PROTECTED], Neil Cerutti [EMAIL PROTECTED] wrote: On 2007-08-01, beginner [EMAIL PROTECTED] wrote: Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. A C-like trick might be helpful while refactoring: working code if False: non-working code You have to indent all the non-working code by one level, but with a good editor that's a snap. Python will still parse the following lines (it must be valid Python syntax), but the resulting parse tree won't be executed. . . . I want to re-emphasize the triple-quote it tip mentioned earlier in this thread. I think the original questioner will find this quite satisfying, if I understand his situ- ation at all. *I* certainly have source code with embedded junk commented out as multi-line strings. I used to do that, but now that I use doctests so much it's infeasible to comment out arbitrary code that way, since they can't necessarily nest. But Diez suggestion is even easier than the if False suggestion I made. -- Neil Cerutti -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
beginner [EMAIL PROTECTED] writes: Thanks everyone for responding. It doesn't look like python has it. I would definitely miss it. As Steve said, the nice thing about __END__ is that things below __END__ do not have to have legit syntax. I think the unaddressed question is: Why is there so much code in your module with invalid syntax that this trick would be useful? That let me focus on the lines of code I am debugging and do not have to worry about some bad syntax down the line. This feature is especially handy if I am, saying, replacing modoules or changing data structures. I would strongly recommend you examine what part of your practice is leading you to write so much code with invalid syntax, without immediately testing and fixing it. Eliminate that part of the process — possibly with test-driven development. -- \Holy unrefillable prescriptions, Batman! -- Robin | `\ | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Python end of file marker similar to perl's __END__
Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? Thanks, Geoffrey -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
On Aug 1, 5:53 am, beginner [EMAIL PROTECTED] wrote: Hi All, This is just a very simple question about a python trick. In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? Thanks, Geoffrey I wished from something like that. What you can do at the moment, is to comment or triple quote the code you don't want to run. Michele Simionato -- http://mail.python.org/mailman/listinfo/python-list
Re: Python end of file marker similar to perl's __END__
In perl, I can write __END__ in a file and the perl interpreter will ignore everything below that line. This is very handy when testing my program. Does python have something similar? Sorry, no, it doesn't. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
