CODEWITHSUNDEEP
pythonpyparsing
Vu Nguyen
Vu Nguyen

Reputation: 1007

Using escChar and escQuote in pyparsing

I am trying to parse a string that may consist of some escape characters like \" \". For example,

"this is an \"example\" of what I want to parse"

I currently have the following parse rule but it cannot handle the escape characters \" QuotedString('"',multiline=True)

There are options for escChar and escQuote and such for the QuotedString class but I am not sure what to use there.

A complete example of what I want to do 

def test1():
    str_ = QuotedString('"',escChar='\\',multiline=True)
    decl = (Keyword("FIELD1") + str_ + ';') | \
        (Keyword("FIELD2") + str_ + ';') 
    G = OneOrMore(decl)

    s = """
FIELD1 "hello world";

FIELD2 "an example of \"what\" I want to parse";
"""

    print G.parseString(s)
    # Only print ['FIELD1', 'hello \nworld', ';']

Upvotes: 2

Views: 1318

Answers (1)

PaulMcG
PaulMcG

Reputation: 63747

The docstring for QuotedString gives:

 |  __init__(self, quoteChar, escChar=None, escQuote=None, multiline=False, unquoteResults=True, endQuoteChar=None)
 |      Defined with the following parameters:
 |       - quoteChar - string of one or more characters defining the quote delimiting string
 |       - escChar - character to escape quotes, typically backslash (default=None)
 |       - escQuote - special quote sequence to escape an embedded quote string (such as SQL's "" to escape an embedded ") (default=None)
 |       - multiline - boolean indicating whether quotes can span multiple lines (default=False)
 |       - unquoteResults - boolean indicating whether the matched text should be unquoted (default=True)
 |       - endQuoteChar - string of one or more characters defining the end of the quote delimited string (default=None => same as quoteChar)
 |

Some interactive interpreter experiments:

>>> import pyparsing
>>> s = r'''"this is an \"example\" of what I want to parse" '''
>>> pyparsing.QuotedString('"').parseString(s)
(['this is an \\'], {})
>>> pyparsing.QuotedString('"', escChar='\\').parseString(s)
(['this is an "example" of what I want to parse'], {})

I can't say that the constructor args for all the classes are 100% complete, but probably >90%.

Upvotes: 1

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