example of parsimonious

example.py

from parsimonious.grammar import Grammar

conf = """diag read interface-id 1
 enable
!
interfae vlan 1
!
interface ip hoo
 interface id
 interface route
!
"""


class VdxConfig(object):
    def __init__(self):
        """
        blocks = (newline* block (newline block)* newline*)
        block = (text continuation_line* newline block_close)
        continuation_line = (newline indent text)
        text = (token (space token)*)
        block_close = "!"
        indent = " "
        newline = "\\n"
        space = ~r" +"
        token = ~r"[a-zA-Z0-9/-]+"
        number = ~r"[0-9]+"
        """

    def loads(self, node):
        if isinstance(node, str):
            node = Grammar(self.__init__.__doc__).parse(node)
        method = getattr(self, node.expr_name, self.default)
        return method(node, [self.loads(n) for n in node])

    def blocks(self, node, children):
        # remove newline of beggining & ending
        return children[1:-1]

    def default(self, node, children):
        return children
    def block_close(self, node, children):
        return "!"
    def indent(self, node, children):
        return " "
    def newline(self, node, children):
        return "\n"
    def space(self, node, children):
        return " "
    def token(self, node, children):
        return node.text
    def number(self, node, children):
        return node.text

def main():
    vdx = VdxConfig()
    print(vdx.loads(conf))

if __name__ == "__main__":
    main()