Can you access registers from python functions in vim

Question

It seems vims python sripting is designed to edit buffer and files rather than work nicely with vims registers. You can use some of the vim packages commands to get access to the registers but its not pretty.

My solution for creating a vim function using python that uses a register is something like this.

function printUnnamedRegister()
python <<EOF
print vim.eval('@@')
EOF
endfunction

Setting registers may also be possible using something like

function setUnnamedRegsiter()
python <<EOF
s = "Some \"crazy\" string\nwith interesting characters"
vim.command('let @@="%s"' % myescapefn(s) )
EOF
endfunction

However this feels a bit cumbersome and I'm not sure exactly what myescapefn should be. So I've never been able to get the setting version to work properly.

So if there's a way to do something more like

function printUnnamedRegister()
python <<EOF
print vim.getRegister('@')
EOF
endfunction

function setUnnamedRegsiter()
python <<EOF
s = "Some \"crazy\" string\nwith interesting characters"
vim.setRegister('@',s)
EOF
endfunction

Or even a nice version of myescapefn I could use then that would be very handy.

UPDATE:

Based on the solution by ZyX I'm using this piece of python

def setRegister(reg, value):
  vim.command( "let @%s='%s'" % (reg, value.replace("'","''") ) )

Answer 1

If you use single quotes everything you need is to replace every occurence of single quote with two single quotes. Something like that:

python import vim, re
python def senclose(str): return "'"+re.sub(re.compile("'"), "''", str)+"'"
python vim.command("let @r="+senclose("string with single 'quotes'"))