Newbie needs help with regex strings

[Paul McGuire]

This isn't a regex solution, but uses pyparsing instead.  Pyparsing
helps you construct recursive-descent parsers, and maintains a code
structure that is easy to compose, read, understand, maintain, and
remember what you did 6-months after you wrote it in the first place.

Download pyparsing at http://pyparsing.sourceforge.net.

-- Paul


data = """pie=apple,quantity=1,cooked=yes,ingredients='sugar and
cinnamon'
Pie=peach,quantity=2,ingredients='peaches,powdered sugar'
Pie=cherry,quantity=3,cooked=no,price=5,ingredients='cherries and
sugar'"""

from pyparsing import CaselessLiteral, Literal, Word, alphas, nums,
oneOf, quotedString, \
        Group, Dict, delimitedList, removeQuotes

# define basic elements for parsing
pieName = Word(alphas)
qty = Word(nums)
yesNo = oneOf("yes no",caseless=True)
EQUALS = Literal("=").suppress()

# define separate pie attributes
pieEntry         = CaselessLiteral("pie") + EQUALS + pieName
qtyEntry         = CaselessLiteral("quantity") + EQUALS + qty
cookedEntry      = CaselessLiteral("cooked") + EQUALS + yesNo
ingredientsEntry = CaselessLiteral("ingredients") + EQUALS +
quotedString.setParseAction(removeQuotes)
priceEntry       = CaselessLiteral("price") + EQUALS + qty

# define overall list of alternative attributes
pieAttribute = pieEntry | qtyEntry | cookedEntry | ingredientsEntry |
priceEntry

# define each line as a list of attributes (comma delimiter is the
default), grouping results by attribute
pieDataFormat = delimitedList( Group(pieAttribute) )

# parse each line in the input string, and create a dict of the results
for line in data.split("\n"):
    pieData = pieDataFormat.parseString(line)
    pieDict = dict( pieData.asList() )
    print pieDict

''' prints out:
{'cooked': 'yes', 'ingredients': 'sugar and cinnamon', 'pie': 'apple',
'quantity': '1'}
{'ingredients': 'peaches,powdered sugar', 'pie': 'peach', 'quantity':
'2'}
{'cooked': 'no', 'price': '5', 'ingredients': 'cherries and sugar',
'pie': 'cherry', 'quantity': '3'}
'''