topic Optimum python IDE for debugging? in Python Questions

Optimum python IDE for debugging?

JT2 — Thu, 28 Feb 2013 10:25:58 GMT

What is ESRI's 'official' stance for which Python environment to debug in? Pythonwin seems to be advocated, but I've noticed there are others such as pyscripter. Which one offers the best debugging environment? And the best intellisense / autocompletion?

I see there is some guidance here http://blogs.esri.com/esri/arcgis/2010/09/14/review-of-ides-for-python/ but I really think that ESRI needs to take a more proactive stance here, because Python adoption is surely premised on the quality of the tools that we can use to debug, which at the moment is nowhere near as easy as say VBA or Visual Studio.

Re: Optimum python IDE for debugging?

DanPatterson_Retired — Thu, 28 Feb 2013 10:39:36 GMT

Each person has their own preferences, however, the quality of the debugging capabilities might depend upon how well one writes code. Often, Notepad works fine for me.

Re: Optimum python IDE for debugging?

JamesCrandall — Thu, 28 Feb 2013 11:15:12 GMT

TextPad for me -- the line and space numbers help with formatting and alignment.

It's been challenging, but not overwhelmingly difficult to adjust --- most of my career has been developing COM/ArcObjects using languages that don't care about formatting and super functional IDE's.

Re: Optimum python IDE for debugging?

MaraStoica1 — Thu, 28 Feb 2013 12:49:36 GMT

There are some good ones out there if you're willing to spend a little money. PyCharm and WingIDE are the 2 I've heard the best things about. They both have free trials available.

If you want free, I'd recommend PyScripter. It's not as good as the ones mentioned above, but it gets the job done, and it sure beats IDLE

Re: Optimum python IDE for debugging?

JohnDye — Thu, 28 Feb 2013 15:09:41 GMT

PyScripter is the current apple of my eye.

Re: Optimum python IDE for debugging?

MarcoBoeringa — Thu, 28 Feb 2013 15:51:37 GMT

I have only used it sparingly, but from the different "standard" IDEs I installed and tried, I also found PyScripter one of the more useful ones to work with while debugging. Nice interception and launch of PyScripter once debugging is setup and you try to run a script from ArcGIS that needs debugging.

Re: Optimum python IDE for debugging?

JT2 — Fri, 01 Mar 2013 07:06:03 GMT

Thanks everyone. I will be sure to check out some of these programs.

So, what is the solution for the annoying problem when debugging in the Python window...when it counts lines by ignoring blank lines, whereas your script editor usually counts line numbers including the blanks? This is a massive usability issue for beginners, when you get a traceback error at line 26 or whatever which doesn't correspond at all to your script in an external editor. Any ideas?

Re: Optimum python IDE for debugging?

BradPosthumus — Fri, 01 Mar 2013 16:17:58 GMT

To answer your original post, sometimes I use Notepad++ but normally I just use PythonWin since it was kind of the default IDE when ESRI brought Python into ArcGIS. I tried switching to other IDE's but I would always end up reverting back to PythonWin. I've grown to like the simplicity of it. At times I'll drop my scripts into the Ninja IDE for when I want my code to conform to the PEP8 coding style guide. It does a good job of highlighting all of the inconsistencies.

As for your second question, I can't recall ever seeing a traceback with the wrong line number, regardless of the number of blank lines. Where are you seeing this happen?

Re: Optimum python IDE for debugging?

JT2 — Sat, 11 Dec 2021 19:17:47 GMT

As for your second question, I can't recall ever seeing a traceback with the wrong line number, regardless of the number of blank lines. Where are you seeing this happen?

Thanks for your reply. Well I get this behaviour consistently, and it can make it VERY difficult to debug because the Python window (for me, at least) ignores blank lines.

Here's a sample script:

for i in range(4):
   print i

print "complete" x

As you can see, there are four lines. It's nice to have blank lines because it helps to organise the code.

Naturally there is a deliberate error, and this is what the Python window says:

>>> for i in range(4):
...    print i
... print "complete" x
... 
Parsing error <type 'exceptions.SyntaxError'>: invalid syntax (line 3)

It says the error is on line 3, when we all know it's on line 4. This is because the Python window ignores blank lines, either when you paste them in, or when you right click and choose Load to open a script.

This is the behaviour that troubles me because all correspondence between errors and the original script is lost, and that is a bad thing because it's very hard to count lines in your original script editor. Any solutions?

Re: Optimum python IDE for debugging?

MathewCoyle — Mon, 04 Mar 2013 13:23:29 GMT

This is the behaviour that troubles me because all correspondence between errors and the original script is lost, and that is a bad thing because it's very hard to count lines in your original script editor. Any solutions?

Debug in your script editor and not ArcGIS?

Re: Optimum python IDE for debugging?

BradPosthumus — Sat, 11 Dec 2021 19:17:49 GMT

Thanks for your reply. Well I get this behaviour consistently, and it can make it VERY difficult to debug because the Python window (for me, at least) ignores blank lines.

Here's a sample script:
for i in range(4):
   print i

print "complete" x
As you can see, there are four lines. It's nice to have blank lines because it helps to organise the code.

Naturally there is a deliberate error, and this is what the Python window says:
>>> for i in range(4):
...    print i
... print "complete" x
... 
Parsing error <type 'exceptions.SyntaxError'>: invalid syntax (line 3)
It says the error is on line 3, when we all know it's on line 4. This is because the Python window ignores blank lines, either when you paste them in, or when you right click and choose Load to open a script.

This is the behaviour that troubles me because all correspondence between errors and the original script is lost, and that is a bad thing because it's very hard to count lines in your original script editor. Any solutions?

Which IDE are you using, if any? It doesn't look like you're actually running your script, but instead you're retyping your code directly into the Python prompt (your second code snippet). In this case it's giving you a legitimate error message - the third line of the code block you typed into the Python prompt has the syntax error. If you add the blank line to your code block, then it tells you the syntax error is on the fourth line (using Python interactive window directly in ArcGIS 10.1):

>>> for i in range(4):
...    print i
... 
... print "complete" x
... 
Parsing error SyntaxError: invalid syntax (line 4)

Your first code snippet presumably is your actual script that you need to run. If you're using an IDE like IDLE or PythonWin, the IDE won't allow you to run it due to the syntax error. Instead the IDE will place the cursor next to the location of the syntax error in the script. If you're not using an IDE and you try running the script using the Windows command line (cmd), it will tell you the syntax error is on line 4. There shouldn't be any case where Python is ignoring blank lines when reporting line numbers in error messages.

Re: Optimum python IDE for debugging?

JT2 — Tue, 05 Mar 2013 12:57:05 GMT

Thanks. I should clarify that I'm running my code within the Python window in ArcGIS (as in Geoprocessing -> Python). This is how I always prototype scripts. I find it superior to using an IDE for testing scripts because a) it's easier to reference objects using their names rather than providing full paths, and b) it's useful to see results appear in the map window. You don't get that kind of visual feedback using an IDE.

So, given the advantages of using the Python window to execute code, even if that means editing and saving that as a script in another application, how can I get it to stop ignoring blank lines when I paste or load a script? Thanks

Re: Optimum python IDE for debugging?

BradPosthumus — Tue, 05 Mar 2013 14:47:18 GMT

I can't seem to reproduce this problem (using 10.1). Here's my workflow:

1. Create a script in notepad or whatever. Insert blank lines somewhere in the script. It can be saved as a Windows file or a UNIX file, it doesn't matter.
2. Load the script in the Python window within ArcMap.
3. Blank lines appear in the Python window. Error messages cite the proper line number.

Same with typing in lines manually. It includes whatever blank lines I enter (using shift-Enter to add blank lines) in the line count. I tried it in 10.0 SP5 as well but I noticed it doesn't return any line numbers in the error message.

Are you using the same type of workflow, with the exception of #3 where the blank lines don't appear in your case?

Re: Optimum python IDE for debugging?

JT2 — Sat, 11 Dec 2021 19:17:52 GMT

Thanks Brad. This is really strange. Attached is my script py (also pasted below, as before), it has a blank line at line 3.

I copy it from notepad and paste into the Python window. As soon as I paste, the blank lines are gone, see picture (attached)

[ATTACH=CONFIG]22395[/ATTACH]

The same behaviour occurs when I right click in the Python window to load the py file. Edit -> Past Special... -> Unicode text also does nothing. I'm on 10.0 SP2.

Why does this happen for me and my colleagues? Thanks

for i in range(4):
   print i

print "complete" x

Re: Optimum python IDE for debugging?

BradPosthumus — Wed, 06 Mar 2013 10:43:41 GMT

I tested your script in 10.1 and 10.0 SP5 and the blank lines appear for me when both pasting in the code and loading it in. Maybe installing SP5 would fix the problem?

As an aside, I noticed in 10.0 the error messages only contain line numbers for syntax errors and not for runtime errors. In 10.1 the line numbers show up in all error messages.

Re: Optimum python IDE for debugging?

JT2 — Wed, 06 Mar 2013 14:06:39 GMT

That's interesting, I wonder if this appears in a list of known issues. Either way, thanks for investigating, Brad.

Re: Optimum python IDE for debugging?

SendhilKolandaivel — Thu, 07 Mar 2013 01:18:31 GMT

I have heard good things about Komodo IDE by ActiveState:

http://www.activestate.com/komodo-ide

It is about $300, and can has code intelligence for a variety of languages including Python, PHP, Perl, Ruby, Tcl, HTML, JavaScript, CSS, XML, XSLT, Node.js, etc.

Sendhil