use of <$nopage> in python try-except block - python

I am seeing use of <$nopage> in some python scripts online and in a pdf file. I have googled for what it stands for. But could not get information about it. To be specific, in the PDF version of the book, Core Python Programming, I see this <$nopage> construct many times. But on the online version (Safari Books) of the same book, I do not see this construct. Can someone please tell me what this <$nopage> means? Thanks.

It means nothing in the context of Python at all. It's probably a mistake in the PDF rendering. I'm guessing it's a statement to prevent page breaks in the code.
Update: I finally found an example here:
http://raninho.com.br/~paper/Python/O%27Reilly%20-%20Core%20Python/237.html
That is indeed not python code, but most likely code to prevent page breaks. Pretend it's not there.

Related

Adding text to a 'paragraph' containing an image using python docx

I'm using python docx which claims in the documentation that:
'Often, a picture is placed in a paragraph by itself, but this is not required. It can have text before and after it in the paragraph in which it’s placed.'
But I cant find out how to do this, could someone explain (idealy with a basic example) how I get text before the image while in the same paragraph please. So the line of text ends with an image.
I've not found any answers to this but have seen people asking the same elsewhere with no solution.
Thanks
(note: I'm not a hugely experiance programmer and other than this awkward part the rest of my code will very basic)
At the time of this writing, python-docx doesn't have the features to support what you're trying to do.
The feature that would support it would be Run.add_picture(). If you add a feature request to the python-docx issue tracker, I'll see how soon we can get to it.
In the meantime, if you wanted to dig in and see what you could hack up, I'd recommend starting here, at Document.add_picture, as the structure would be analogous and use mostly the same calls.
If you just want to write docx files with Python, you can use another module:
https://github.com/rafaels88/py2docx

checking/verifying python code

Python is a relatively new language for me and I already see some of the trouble areas of maintaining a scripting language based project. I am just wondering how the larger community , with a scenario when one has to maintain a fairly large code base written by people who are not around anymore, deals with the following situations:
Return type of a function/method. Assuming past developers didn't document the code very well, this is turning out to be really annoying as I am basically reading code line by line to figure out what a method/function is suppose to return.
Code refactoring: I figured a lot of code need to be moved around, edited/deleted and etc. But lot of times simple errors, which would otherwise be compile time error in other compiled languages e.g. - wrong number of arguments, wrong type of arguments, method not present and etc, only show up when you run the code and the code reaches the problematic area. Therefore, whether a re-factored code will work at all or not can only be known once you run the code thoroughly. I am using PyLint with PyDev but still I find it very lacking in this respect.
You are right, that's an issue with dynamically typed interpreted languages.
There are to important things that can help:
Good documentation
Extensive unit-testing.
They apply to other languages as well of course, but here they are especially important.
As far as I know If code is not documented at all and the author isn't around anymore it's up to you to find out what the ode actually does.
That's why people should always stick to certain guidelindes that can be enforced by stylecheckers like pep8. https://pypi.python.org/pypi/pep8
Comments and docstrings should be included in every method to avoid such situation you're describing. http://www.python.org/dev/peps/pep-0257/#what-is-a-docstring
Also unittests are very helpfull for refactoring since you can check if you broke something with the click of a button. http://docs.python.org/2/library/unittest.html
hope this helps
Others have already mentioned documentation and unit-testing as being the main tools here. I want to add a third: the Python shell. One of the huge advantages of a non-compiled language like Python is that you can easily fire up the shell, import your module, and run the code there to see what it does and what it returns.
Linked to this is the Python debugger: just put import pdb;pdb.set_trace() at any point in your code, and when you run it you will be dropped into the interactive debugger where you can inspect the current values of the variables. In fact, the pdb shell is an actual Python shell as well, so you can even change things there.

Sublime Text editor plug-in, scan div id's and classes

I'm aware I'm supposed to show some starting code to give you a clue as to what I'm trying to do, but I'm really at a basic level and I can't find any resources to show me what I'm after. Basically, I'm trying to write a plug-in for Sublime Text editor, which selects all div ID's then outputs them into a file. What's the best approach? It seems like it should be easy, but I'm not too sure.
Thanks in advance for your help,
Ewan
This looks like a good place to start: http://www.sublimetext.com/docs/plugin-basics
Look at http://www.sublimetext.com/docs/2/api_reference.html, though be advised that Sublime Text 3 is currently in beta. It introduces changes to the plugin api, and a requirement to support Python 3. See http://www.sublimetext.com/docs/3/porting_guide.html
Assuming you have some familiarity with python, I would start with this tutorial on for writing plugins (Link). The author of that tutorial wrote, among other things, package control. Granted, it is for ST2, but for what you are trying to do, I don't for see any major issues with writing a plugin that is compatible with both ST2 and ST3.
How you go about writing your particular plugin is up to you. One approach may be leveraging the view.find_all() method. This takes a regular expression and returns a set of regions. From these regions, you can grab the text, and subsequently the IDs for the divs. There may be a better way, but that might work as an initial attempt. Writing to a file can be done through the usual python means.

bpython-like autocomplete and parameter description in Emacs Python Mode?

I've been using bpython for a while now for all of my Python interpreting needs. It's delightful, particularly when you're using unfamiliar new libraries, or libraries with a multitude of functions. In any case, it's nice to have a bpython interpreter running alongside what I'm doing, but it'd be even better if I had both the autocomplete-like feature, and the parameter description in the manner that bpython does while I'm editing code in Emacs. Am I completely crazy? Does anyone have an idea on how to do this?
Thanks,
Bradley Powers
You're not completely crazy.
python-mode can integrate with eldoc-mode to display the arg spec of the function you're calling at point. Just do M-x eldoc-mode while you're in a python file to turn it on and it should start working. It talks to an inferior python buffer to inspect the functions directly, so it should always be decently accurate. You can turn it on automatically for all new python-mode buffers with (add-hook 'python-mode-hook '(lambda () (eldoc-mode 1)) t) in your emacs startup file. Now, at this point I have to say that I don't do any regular python programming, and that when I tried it just now it didn't work. I spent a few minutes poking around in the source code and everything seems to be in place, but the code that it runs in the inferior process is just returning an empty string. Perhaps it's just my setup, or perhaps I'm reading the wrong source files; it's hard to say.
Emacs provides several different types of expansion/autocompletion. By default you have access to dabbrev-expand by hitting M-/. This is a fairly simple form of completion; it's just meant to work on any old file you happen to edit. More sophisticated is hippie-expand, but even that doesn't do anything python-specific. The documentation says that it can integrate with hippie-expand for exact completions, but this might be a lie; I couldn't figure out how it works. A little poking around shows several related solutions for this, all of which seem to rely on pymacs. If I were going to do a lot of python programming and didn't already have a fairly complicated emacs set up, I'd probably start by installing emacs-for-python. It looks to be a pretty complete setup, and even claims to have live warning/error detection.
In the spirit of helping others to help themselves, I'd like to point out how I came upon all of this information. My first step was to open a file in python-mode. I didn't actually have any python code available, so I just went to my scratch buffer and made it a python buffer (M-x python-mode). Then I asked for help about this strange new mode (C-h m) to see what it could do. It's author has kindly put a brief summary of what the mode can do which mentions eldoc-mode, Imenu, outline-mode, hippie-expand, rlcompleter, abbrev tables, and a bunch of other things. From there I started looking at the source code. For instance, to integrate with eldoc-mode, it defines a function called python-eldoc-function and gives that to the eldoc module for use in python buffers. Reading that code shows me how it interacts with the inferior buffer, etc.
I hope some of this helps.

Indent guide plugin for gedit (python)

screenshot http://www.activestate.com/padfiles/komodo_edit/komodo_edit_linux.png
See the indent guides? They're damn helpful when writing Python code. Any chance I could get something similar for gedit? I wouldn't mind having to write my own plugin, as long as it's in Python... So:
Is there a plugin for this which works with gedit?
If not, would it be possible to write one in Python.
There's a huge list of GEdit plugins here:
https://wiki.gnome.org/Apps/Gedit/Plugins
I haven't looked through them in a while, but I don't remember any implementing indentation guides. Many plugins are written in Python, so there are some good examples if you want to implement your own.

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