Execute Python from within current file

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created November 28, 2003 · complexity intermediate · author Steve Halpin · version 6.0

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Inspired by VimTip608.

To execute Python from a range within the current text file and write the output to that file (replacing the Python), add the snippet below to .vimrc (or other suitable *rc file).

Requires a 'proper' Python setup so that the imported modules can be found.

I find it a handy intermediate step between using the Python interpreter on command line and running a complete script. Can be used for easy buffer manipulation, filtering input, preprocessing text and templating-like tasks.

python << EOL
import vim, StringIO,sys
def PyExecReplace(line1,line2):
  r = vim.current.buffer.range(int(line1),int(line2))
  redirected = StringIO.StringIO()
  sys.stdout = redirected
  exec('\n'.join(r[:]) + '\n')
  sys.stdout = sys.__stdout__
  output = redirected.getvalue().split('\n')
  r[:] = output[:-1] # the -1 is to remove the final blank line
  redirected.close()
EOL
command -range Pyer python PyExecReplace(<f-line1>,<f-line2>)

Some examples of use

Simple

print 2 + 2

:Pyer

With the cursor on the 'print' line, that line is replaced with 4.

Filter

for line in vim.current.buffer:
 if line[0] != '\t':
  print line

:%Pyer

Filters out lines beginning with a tab in the current buffer.

Inserting time

import time
print time.ctime()

:%Pyer

Replaces line with date/time.

Getting web content without tags

import urllib2,htmllib,formatter
h = htmllib.HTMLParser(formatter.AbstractFormatter(formatter.DumbWriter()))
h.feed(urllib2.urlopen('http://www.somesite.com').read())

:%Pyer

Inserts the web page text, but not the html tags, for a given site.

Comments

I use the following:

"in ~/.vimrc:
"python extensions
py from vim import buffers, windows, command, current, error
py import vim, sys
py from vimpy import *

command! PyExecBuffer py exec('\n'.join(current.buffer))

map <F5> :PyExecBuffer<CR>
imap <F5> <Esc><F5><CR>a

vimpy.py

import sys, vim
class Buffer:
    def __init__(self,buf):
        self.buf=buf
    def write(self,s):
        ll=s.split('\n')
        self.buf[-1]+=ll[0]
        for l in ll[1:]:
            self.buf.append(l)
    def clear(self):
        del self.buf[:]

def redirect(buf=None):
    buf = buf or vim.current.window.buffer
    try:
        sys._stdout
    except:
        sys._stdout=sys.stdout
    sys.stdout = Buffer(buf)

Then I start Vim, create new window (<C-W> N), and do

:py redirect(current.window.buffer)

on a window I want to receive all printed data.

Then <F5> in any buffer executes the buffer contents in Python, output goes to the window selected.

To redirect output back just do sys.stdout = sys._stdout

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