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Escape sequences in vim (neovim) Python feedkeys

I want to be able to control vim/neovim on a per-key basis with python scripting. There is a function called feedkeys in the python vim module (vim.feedkeys) that is nearly what I want. However, I haven't been able to figure out how to send things like function keys, arrow keys, pgup, pgdown etc as it always takes my strings completely literally.
As per the documentation for vim's feedkeys (vimscript version, not python)
feedkeys("\<CR>") simulates pressing of the <Enter> key. But feedkeys('\<CR>') pushes 5 characters.
Things I've tried with the python counterpart that haven't worked (note, <CR> is just an example; I know I can use \n for that. Nonetheless, this should simulate an enter keypress):
vim.feedkeys("\<CR>")
vim.feedkeys("<CR>")
vim.feedkeys("\<CR\>")
vim.call("feedkeys", "\<CR>")
vim.call("feedkeys", '"\<CR>"')
All of these were interpreted literally. I want to do something like
vim.feedkeys("\<F5>") etc. Any ideas?

This isn't ideal, but it solves my issue well enough:
vim.command('call feedkeys("\<F5>")')
In case this is useful to anyone, I've written a general function that will handle the \<> escapes as well as double-quotes:
def fkeys(text):
firstsub = True
for sub in text.split('"'):
if firstsub:
firstsub = False
else:
vim.feedkeys('"')
vim.command(f'call feedkeys("{sub}")')

Sorry for being Captain Obvious, but it doesn't work, because Python is not VimScript.
See :h nvim_replace_termcodes() and :h nvim_feedkeys() for a complete example. In case of <CR>, simply byte value of 13 will do.

You don't, because the interpretation of something like "\<CR>" is a function of VimL string literals. In other words, feedkeys("\<CR>") is the same thing as (probably) feedkeys("\x0d") — the function doesn't see the difference, the interpretation happens at a source code level. Naturally, Python doesn't have the same feature in the same way.
If you don't want to figure out what the escape sequence is for F5 and code it into your Python script, perhaps you could use vim.eval() to eval a VimL expression, e.g. vim.eval(r'feedkeys("\<F5>")').

Is there something similar to __END__ of perl in python? [duplicate]

Am I correct in thinking that that Python doesn't have a direct equivalent for Perl's __END__?
print "Perl...\n";
__END__
End of code. I can put anything I want here.
One thought that occurred to me was to use a triple-quoted string. Is there a better way to achieve this in Python?
print "Python..."
"""
End of code. I can put anything I want here.
"""

The __END__ block in perl dates from a time when programmers had to work with data from the outside world and liked to keep examples of it in the program itself.
Hard to imagine I know.
It was useful for example if you had a moving target like a hardware log file with mutating messages due to firmware updates where you wanted to compare old and new versions of the line or keep notes not strictly related to the programs operations ("Code seems slow on day x of month every month") or as mentioned above a reference set of data to run the program against. Telcos are an example of an industry where this was a frequent requirement.
Lastly Python's cult like restrictiveness seems to have a real and tiresome effect on the mindset of its advocates, if your only response to a question is "Why would you want to that when you could do X?" when X is not as useful please keep quiet++.

The triple-quote form you suggested will still create a python string, whereas Perl's parser simply ignores anything after __END__. You can't write:
"""
I can put anything in here...
Anything!
"""
import os
os.system("rm -rf /")
Comments are more suitable in my opinion.
#__END__
#Whatever I write here will be ignored
#Woohoo !

What you're asking for does not exist.
Proof: http://www.mail-archive.com/python-list#python.org/msg156396.html
A simple solution is to escape any " as \" and do a normal multi line string -- see official docs: http://docs.python.org/tutorial/introduction.html#strings
( Also, atexit doesn't work: http://www.mail-archive.com/python-list#python.org/msg156364.html )

Hm, what about sys.exit(0) ? (assuming you do import sys above it, of course)
As to why it would useful, sometimes I sit down to do a substantial rewrite of something and want to mark my "good up to this point" place.
By using sys.exit(0) in a temporary manner, I know nothing below that point will get executed, therefore if there's a problem (e.g., server error) I know it had to be above that point.
I like it slightly better than commenting out the rest of the file, just because there are more chances to make a mistake and uncomment something (stray key press at beginning of line), and also because it seems better to insert 1 line (which will later be removed), than to modify X-many lines which will then have to be un-modified later.
But yeah, this is splitting hairs; commenting works great too... assuming your editor supports easily commenting out a region, of course; if not, sys.exit(0) all the way!

I use __END__ all the time for multiples of the reasons given. I've been doing it for so long now that I put it (usually preceded by an exit('0');), along with BEGIN {} / END{} routines, in by force-of-habit. It is a shame that Python doesn't have an equivalent, but I just comment-out the lines at the bottom: extraneous, but that's about what you get with one way to rule them all languages.

Python does not have a direct equivalent to this.
Why do you want it? It doesn't sound like a really great thing to have when there are more consistent ways like putting the text at the end as comments (that's how we include arbitrary text in Python source files. Triple quoted strings are for making multi-line strings, not for non-code-related text.)
Your editor should be able to make using many lines of comments easy for you.

Cannot create a string with "#" symbol inside the text in Pydev

I'm trying to create a simple string like:
test = "abc#email.com" in Pydev but it automatically interpret "#" as a special symbol and the statement cannot pe done.
When I focus on the variable in Pydev, I can see:
test = "abc*#email.com"* instead of test = "abc#email.com"
Anyone has any idea why I have this issue?
If I run the statement in windows command prompt python, then it is correctly assigned.
Does it have any relation with pylint?
Thanks,

The only way I was able to reproduce similar result was with unclosed string before that, which is obviously a syntax error. Otherwise I've never seen any problems with string literals containing # while using PyDev (with PyLint).

try %#?
this might be your answer. Not a whole lot out there about special characters in python.

How to recognize special eol character when I see it, using Python?

I'm scraping a set of originally pdf files, using Python. Having gotten them to text, I had a lot of trouble getting the line endings out. I couldn't figure out what the line separator was. The trouble is, I still don't know.
It's not a '\n', or, I don't think, '\r\n'. However, I've managed to isolate one of these special characters. I literally have it in memory, and by doing a call to my_str.replace(eol, ''), I can remove all of these characters from one of my files.
So my question is open-ended. I'm a bit lost when it comes to unicode and such. How can I identify this character in my files without resorting to something ridiculous, like serializing it and then reading it in? Is there a way I can refer to it as a code, perhaps? I can't get Python to yield what it actually IS. All I ever see if I print it, or call unicode(special_eol) is the character in its functional usage as a newline.
Please help! Thanks, and sorry if I'm missing something obvious.

To determine what specific character that is, you can use str.encode('unicode_escape') or repr() to get (in Python 2) a ASCII-printable representation of the character:
>>> print u'☃'.encode('unicode_escape')
\u2603
>>> print repr(u'☃')
u'\u2603'

how does IPython's ? (question mark) operator actually work?

So i was thinking that in order to implement such a feature in a console application , where appending a question mark at the end of a function name will pour out it's doc string , i would have probably used a feature like metaclasses , where upon definition/import , i'd duplicate all the module member names and produce new ones just for typing out doc strings.
Then i noticed that you don't need actual parenthesis to call the helper functions and python doesn't actually allow you to put a question mark at the end of the function name anyway.... So is this done in python or am i just wasting my time trying to figure this out?
Thanks in advance

It's not done the way you're imagining. ipython reads your command prompt input as a line of text, so it has a chance to check if it ends with a question mark before it passes it on to eval (or whatever). If it does, it runs help(name) instead of what you typed.
AST looks a little heavy-duty, but you can get a feel for how this works by checking out the module code. It gives you a lightweight interpreter that you can extend with syntax of this sort if you want.

Have a look at the IPython.core.inputsplitter module for the code that parses the raw input line for things like ?, !, /, %, etc.

ipython uses AST, you can customize the syntax parsing and create a new ipython fork.
may help