Python and vim: Two great tastes that go great together
Sean Reifschneider
tummy.com, ltd.
And now for something completely different...
Presentation Overview
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10 to 15 minutes of slides and examples.
15 to 20 minutes audience-directed.
What?
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Python scripting in vim.
(Not coding Python with vim)
vim compiled with "+python"
As present in:
Fedora/CentOS (vim-enhanced)
Debian/Ubuntu (vim-python) "Macros" in vim, but with a serious language behind them Like Emacs use of LISP (but, you know, better :-) More powerful than "vim script" Much more familiar to Python programmers than "vim script"
Example: Auto Indentation Settings
" indent.vimrc
autocmd BufRead * python setIndentation()
python << EOF
def setIndentation():
import vim
maxSearch = 1000 # max number of lines to search through
indentSpaces = None
cb = vim.current.buffer
indentCount = { ' ' : 0, '\t' : 0 }
justSawDefOrClassLine = 0
for i in xrange(0, min(maxSearch, len(cb))):
line = cb[i]
if not line: continue
Example: Auto Indentation Settings (cont)
#for i in xrange(0, min(maxSearch, len(cb))): [CONTINUED]
# count spaces after a class or def line
if justSawDefOrClassLine:
justSawDefOrClassLine = 0
if line[0] == ' ':
indentSpaces = 0
for c in line:
if c != ' ': break
indentSpaces = indentSpaces + 1
if line[:4] == 'def ' or line[:6] == 'class ':
justSawDefOrClassLine = 1
vim script You May Want To Use
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autocmd FileType python [commands]
Run commands when this type of file is edited python [python code]
Evaluate the python code given python << EOF
Read python commands until a line with "EOF" is read pyfile [filename]
Read python commands from a python file map [keys] [command]
Run the specified command when the key(s) are pressed
Example: Auto Indentation Settings (cont)
#for i in xrange(0, min(maxSearch, len(cb))): [CONTINUED]
# add to tab versus space count
if line[0] in ' \t':
indentCount[line[0]] = indentCount.get(line[0], 0) + 1
# more lines started with space
if indentCount[' '] > indentCount['\t']:
vim.command('set smarttab tabstop=8 expandtab')
if indentSpaces:
vim.command('set ts=%d sw=%d' % ( indentSpaces, indentSpaces ))
# more lines started with tab
else:
vim.command('set softtabstop=3 ts=3 sw=3')
EOF
Python+vim Code Scraps
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import vim
Load the vim Python module vim.current.line
The current line in the editor vim.current.buffer
A list-like object of all lines in the buffer vim.current.buffer
A list-like object of all lines in the buffer lineno, col = vim.current.window.cursor
Get location of cursor vim.current.window.cursor = lineno, col
Change location of cursor vim.command(str(Command))
Run a vim command (like typing ":Command" in vim) vim.eval(str(vimExpression))
Return the value of the vim expression
tabSize = vim.eval('&ts') vim.error
Exception raised when the vim module has problems
Example: DNS Serial Update
" dns.vimrc
autocmd FileType dns map S :python updateDnsSerial()^M
python << EOF
def updateDnsSerial():
import re, time, vim, string
maxSearch = 20
cb = vim.current.buffer
foundSoa = 0
for i in xrange(0, min(maxSearch, len(cb))):
line = cb[i]
if foundSoa:
# look for serial
rx = re.match(r'^\s*(\d+).*', line)
if not rx:
print 'Unable to find Serial'
return
serial = rx.group(1)
Example: DNS Serial Update (cont)
#for i in xrange(0, min(maxSearch, len(cb))): [CONTINUED]
# generate new serial
now = time.time()
today = time.strftime('%Y%m%d00', time.localtime(now))
todayVal = long(today)
serialVal = long(serial)
if todayVal <= serialVal: todayVal = serialVal + 1
# update serial
cb[i] = string.replace(line, serial, '%d' % todayVal)
# display update string
print 'Updated serial from "%s" to "%d"' % ( serial, todayVal )
break
if re.match(r'^@\s+IN\s+SOA\s+', line): foundSoa = 1
EOF
vim Buffer Use
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lines = vim.current.buffer[1] = str(newLine)
Replace a line lines = vim.current.buffer[10:11] = [str(newLine1), newLine2]
Replace many lines del(lines[10])
Delete a line del(lines[10:20])
Delete 10 lines
Example: Python Block Motion
" pyblock.vim
map ( :python pythonblockFind(forward = 0)^M
map ) :python pythonblockFind()^M
python << EOF
def countIndent(line):
i = 0
for s in line:
if s != ' ' and s != '\t': return(i)
i = i + 1
return(0)
def isEmptyLine(line):
return(not line.strip())Example: Python Block Motion (cont)
def pythonblockNonblank(lineno, forward = 1):
import vim
cb = vim.current.buffer
col = vim.current.window.cursor[1]
end, increment = ( 0, -1 )
if forward == 1: end, increment = ( len(cb), 1 )
for i in xrange(lineno, end, increment):
cline = cb[i - 1]
if not isEmptyLine(cline):
if i >= len(cb): i = len(cb) - 1
if i < 1: i = 1
vim.current.window.cursor = ( i, col )
return()Example: Python Block Motion (cont)
def pythonblockFind(forward = 1):
import vim
cb = vim.current.buffer
lineno, col = vim.current.window.cursor
cline = cb[lineno - 1]
cIndent = countIndent(cline)
end, increment = ( 0, -1 )
if forward == 1: end, increment = ( len(cb), 1 )
for i in xrange(lineno, end, increment):
cline = cb[i - 1]
if isEmptyLine(cline): continue
if countIndent(cline) < cIndent:
if forward == 1:
return(pythonblockNonblank(i - 1, not forward))
return(pythonblockNonblank(i + 1, not forward))
if forward == 1: vim.current.window.cursor = ( len(cb) - 1, col )
else: vim.current.window.cursor = ( 1, col )
EOFHOWTO Get Started
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Not very well documented outside of vim.
In vim: help python
Look at other python scripts at vim.org
Audience Directed
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Questions?
Topics?