pedit

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vim: ts=4
#
# Copyright (c) 2007-2008 Benjamin Schweizer.
#
# Abstract
# ~~~~~~~~
# an interactive editor for pickle encoded data structures
#
# Authors
# ~~~~~~~
# Benjamin Schweizer, http://benjamin-schweizer.de/contact
#
# Changes
# ~~~~~~~
# 2008-11-13, benjamin: added NoneType
# 2007-10-15, benjamin: fixed environment bug (thanx hautzi)
# 2007-09-28, benjamin: fixed bug on file creation
# 2007-06-18, benjamin: added multi file edit
# 2007-06-05, benjamin: reworked indent
# 2007-06-04, benjamin: initial release
#
# Todo
# ~~~~~
# - testing, especially indent()
# - error handling
#

import sys
import tempfile
import subprocess
import os
import pickle
import types

def usage():
	print """Copyright (c) 2007 Benjamin Schweizer. All rights reserved.

pedit - an interactive editor for pickle encoded data structures

usage:

	pedit FILENAME [FILENAME FILENAME ...]

"""

def indent(data, level=0, bol=True):
	"""poor man's indent"""
	def escape(str):
		"""string escape"""

		newstr = ''
		for c in str:
			if ord(c) in range(128):
				newstr += c
			else:
				newstr += '\\x%2x' % ord(c)
		str = newstr
		
		if '\r' in str or '\n' in str:
			return '"""%s"""' % str
		else:
			return '"%s"' % str.replace('"', '\\"')

	result = ''
	if bol:
		result += '  ' * level

	if type(data) == types.ListType:
		if not len(data):
			result += '[]'
		else:
			result += '[\n'
			for e in data:
				result += indent(e, level+1)
			result += '  ' * level + ']'
	elif type(data) == types.DictType:
		if not len(data):
			result += '{}'
		else:
			result += '{\n'
			for k in data:
				v = data[k]
				result += '  ' * (level+1) + '%s: ' % escape(k)
				result += indent(v, level+1, bol=False)
			result += '  ' * level + '}'
	elif type(data) == types.TupleType:
		if not len(data):
			result += '()'
		else:
			result += '(\n'
			for e in data:
				result += indent(e, level+1)
			result += '  ' * level + ')'
	elif type(data) == types.IntType:
		result += '%d' % data
	elif type(data) == types.LongType:
		result += '%dL' % data
	elif type(data) == types.FloatType:
		result += '%f' % data
	elif type(data) == types.BooleanType:
		result += '%s' % data
	elif type(data) == types.StringType:
		result += '%s' % escape(data)
	elif type(data) == types.UnicodeType:
		result += 'u%s' % escape(data)
	elif type(data) == types.NoneType:
		result += 'None'
	else:
		raise Exception('unhandeled data type, %s' % type(data))

	if level:
		result += ','
	result += '\n'

	return result


if __name__ == '__main__':
	temp_filenames = {}	# source_filename: temp_filename

	if len(sys.argv) < 2 or '--help' in sys.argv:
		usage()
		sys.exit(1)

	for source_filename in sys.argv[1:]:
		if source_filename[0] == '-':
			break

		# load pickle data
		try:
			fh = open(source_filename, 'rb')
			data = pickle.load(fh)
			fh.close()
		except IOError, error:
			if not error.errno == 2:
				raise
			# else: file not found
			data = False

		# export pretty printed data
		fd, temp_filename = tempfile.mkstemp()
		fh = os.fdopen(fd, "w+b")
		fh.write('# %s - pedit\n\n' % source_filename)
		fh.write(indent(data))
		fh.write('\n# eof.')
		fh.close()

		temp_filenames[source_filename] = temp_filename
	
	if not temp_filenames:
		usage()
		sys.exit(1)

	# edit tempfiles
	editor = 'vi'
	if 'EDITOR' in os.environ:
		editor = os.environ['EDITOR']
	process = subprocess.Popen([editor] + temp_filenames.values())
	process.communicate()
	# process.wait()

	# update sources
	for source_filename in temp_filenames:
		temp_filename = temp_filenames[source_filename]
		# re-import sourcefile (slow but cleaner code)
		try:
			fh = open(source_filename, 'rb')
			source_data = pickle.load(fh)
			fh.close()
		except IOError, error:
			if not error.errno == 2:
				raise
			# else: file not found
			source_data = False

		# import tempfile
		fh = open(temp_filename, "rb")
		temp_data = eval(fh.read())
		fh.close()

		if source_data != temp_data:
			print "updating '%s'" % source_filename
			fh = open(source_filename, 'wb')
			pickle.dump(temp_data, fh)
			fh.close()
		else:
			print "ignoring '%s' (nothing changed)" % source_filename

		os.unlink(temp_filename)

# eof.