help with pyparsing

P

Prabhu Gurumurthy

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

All,

I have the following lines that I would like to parse in python using
pyparsing, but have some problems forming the grammar.

Line in file:
table <ALINK> const { 207.135.103.128/26, 207.135.112.64/29 }
table <INTRANET> persist { ! 10.200.2/24, 10.200/22 }
table <RFC_1918> const { 192.168/16, ! 172.24.1/29, 172.16/12, 169.254/16 }
table <DIALER> persist { 10.202/22 }
table <RAVPN> const { 10.206/22 }
table <KS> const { \
10.205.1/24, \
169.136.241.68, \
169.136.241.70, \
169.136.241.71, \
169.136.241.72, \
169.136.241.75, \
169.136.241.76, \
169.136.241.77, \
169.136.241.78, \
169.136.241.79, \
169.136.241.81, \
169.136.241.82, \
169.136.241.85 }

I have the following grammar defn.

tableName = Word(alphanums + "-" + "_")
leftClose = Suppress("<")
rightClose = Suppress(">")
key = Suppress("table")
tableType = Regex("persist|const")
ip4Address = OneOrMore(Word(nums + "."))
ip4Network = Group(ip4Address + Optional(Word("/") +
OneOrMore(Word(nums))))
temp = ZeroOrMore("\\" + "\n")
tableList = OneOrMore(Optional("\\") |
ip4Network | ip4Address | Suppress(",") | Literal("!"))
leftParen = Suppress("{")
rightParen = Suppress("}")

table = key + leftClose + tableName + rightClose + tableType + \
leftParen + tableList + rightParen

I cannot seem to match sixth line in the file above, i.e table name with
KS, how do I form the grammar for it, BTW, I still cannot seem to ignore
comments using table.ignore(Literal("#") + restOfLine), I get a parse error.

Any help appreciated.
Thanks
Prabhu
- -
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.4-svn0 (GNU/Linux)
Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org

iD8DBQFHXMhFTkjpaeKzB9YRAmZYAJ9Lyys6+xCrGEsyy33AoRWVdUOXQwCfTG9Q
/f7JZ2pAW6WDSzs79jbDFQE=
=CGb0
-----END PGP SIGNATURE-----
 
C

Chris

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

All,

I have the following lines that I would like to parse in python using
pyparsing, but have some problems forming the grammar.

Line in file:
table <ALINK> const { 207.135.103.128/26, 207.135.112.64/29 }
table <INTRANET> persist { ! 10.200.2/24, 10.200/22 }
table <RFC_1918> const { 192.168/16, ! 172.24.1/29, 172.16/12, 169.254/16 }
table <DIALER> persist { 10.202/22 }
table <RAVPN> const { 10.206/22 }
table <KS> const { \
10.205.1/24, \
169.136.241.68, \
169.136.241.70, \
169.136.241.71, \
169.136.241.72, \
169.136.241.75, \
169.136.241.76, \
169.136.241.77, \
169.136.241.78, \
169.136.241.79, \
169.136.241.81, \
169.136.241.82, \
169.136.241.85 }

I have the following grammar defn.

tableName = Word(alphanums + "-" + "_")
leftClose = Suppress("<")
rightClose = Suppress(">")
key = Suppress("table")
tableType = Regex("persist|const")
ip4Address = OneOrMore(Word(nums + "."))
ip4Network = Group(ip4Address + Optional(Word("/") +
OneOrMore(Word(nums))))
temp = ZeroOrMore("\\" + "\n")
tableList = OneOrMore(Optional("\\") |
ip4Network | ip4Address | Suppress(",") | Literal("!"))
leftParen = Suppress("{")
rightParen = Suppress("}")

table = key + leftClose + tableName + rightClose + tableType + \
leftParen + tableList + rightParen

I cannot seem to match sixth line in the file above, i.e table name with
KS, how do I form the grammar for it, BTW, I still cannot seem to ignore
comments using table.ignore(Literal("#") + restOfLine), I get a parse error.

Any help appreciated.
Thanks
Prabhu
- -
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.4-svn0 (GNU/Linux)
Comment: Using GnuPG with SUSE -http://enigmail.mozdev.org

iD8DBQFHXMhFTkjpaeKzB9YRAmZYAJ9Lyys6+xCrGEsyy33AoRWVdUOXQwCfTG9Q
/f7JZ2pAW6WDSzs79jbDFQE=
=CGb0
-----END PGP SIGNATURE-----
Click to expand...

Shouldn't tableList be 'ZeroOrMore' instead...
 
P

Paul McGuire

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

All,

I have the following lines that I would like to parse in python using
pyparsing, but have some problems forming the grammar.

Line in file:
table <ALINK> const { 207.135.103.128/26, 207.135.112.64/29 }
table <INTRANET> persist { ! 10.200.2/24, 10.200/22 }
table <RFC_1918> const { 192.168/16, ! 172.24.1/29, 172.16/12, 169.254/16 }
table <DIALER> persist { 10.202/22 }
table <RAVPN> const { 10.206/22 }
table <KS> const { \
10.205.1/24, \
169.136.241.68, \
169.136.241.70, \
169.136.241.71, \
169.136.241.72, \
169.136.241.75, \
169.136.241.76, \
169.136.241.77, \
169.136.241.78, \
169.136.241.79, \
169.136.241.81, \
169.136.241.82, \
169.136.241.85 }

I have the following grammar defn.

tableName = Word(alphanums + "-" + "_")
leftClose = Suppress("<")
rightClose = Suppress(">")
key = Suppress("table")
tableType = Regex("persist|const")
ip4Address = OneOrMore(Word(nums + "."))
ip4Network = Group(ip4Address + Optional(Word("/") +
OneOrMore(Word(nums))))
temp = ZeroOrMore("\\" + "\n")
tableList = OneOrMore(Optional("\\") |
ip4Network | ip4Address | Suppress(",") | Literal("!"))
leftParen = Suppress("{")
rightParen = Suppress("}")

table = key + leftClose + tableName + rightClose + tableType + \
leftParen + tableList + rightParen

I cannot seem to match sixth line in the file above, i.e table name with
KS, how do I form the grammar for it, BTW, I still cannot seem to ignore
comments using table.ignore(Literal("#") + restOfLine), I get a parse error.

Any help appreciated.
Thanks
Prabhu
Click to expand...

Prabhu -

This is a good start, but here are some suggestions:

1. ip4Address = OneOrMore(Word(nums + "."))

Word(nums+".") will read any contiguous set of characters in the
string nums+".", so OneOrMore is not necessary for reading in an
ip4Address. Just use:

ip4Address = Word(nums + ".")


2. ip4Network = Group(ip4Address + Optional(Word("/") +
OneOrMore(Word(nums))))

Same comment, OneOrMore is not needed for the added value to the
ip4Address:

ip4Network = Group(ip4Address + Optional(Word("/") + Word(nums))))


3. tableList = OneOrMore(Optional("\\") |
ip4Network | ip4Address | Suppress(",") |
Literal("!"))

The list of ip4Networks is just a comma-delimited list, with some
entries preceded with a '!' character. It is simpler to use
pyparsing's built-in helper, delimitedList, as in:

tableList = Group( delimitedList(Group("!"+ip4Network)|ip4Network) )


Yes, I know, you are saying, "but what about all those backslashes?"
The backslashes look like they are just there as line continuations.
We can define an ignore expression, so that the table expression, and
all of its contained expressions, will ignore '\' characters as line
continuations:

table.ignore( Literal("\\") + LineEnd() )

And I'm not sure why you had trouble with ignoring '#' + restOfLine,
it works fine in the program below.

If you make these changes, your program will look something like this:

tableName = Word(alphanums + "-" + "_")
leftClose = Suppress("<")
rightClose = Suppress(">")
key = Suppress("table")
tableType = Regex("persist|const")
ip4Address = Word(nums + ".")
ip4Network = Group(ip4Address + Optional(Word("/") + Word(nums)))
tableList = Group(delimitedList(Group("!"+ip4Network)|ip4Network))
leftParen = Suppress("{")
rightParen = Suppress("}")

table = key + leftClose + tableName + rightClose + tableType + \
leftParen + tableList + rightParen
table.ignore(Literal("\\") + LineEnd())
table.ignore(Literal("#") + restOfLine)

# parse the input line, and pprint the results
result = OneOrMore(table).parseString(line)
from pprint import pprint
pprint(result.asList())

Prints out:
['ALINK',
'const',
[['207.135.103.128', '/', '26'], ['207.135.112.64', '/', '29']],
'INTRANET',
'persist',
[['!', ['10.200.2', '/', '24']], ['10.200', '/', '22']],
'RFC_1918',
'const',
[['192.168', '/', '16'],
['!', ['172.24.1', '/', '29']],
['172.16', '/', '12'],
['169.254', '/', '16']],
'DIALER',
'persist',
[['10.202', '/', '22']],
'RAVPN',
'const',
[['10.206', '/', '22']],
'KS',
'const',
[['10.205.1', '/', '24'],
['169.136.241.68'],
['169.136.241.70'],
['169.136.241.71'],
['169.136.241.72'],
['169.136.241.75'],
['169.136.241.76'],
['169.136.241.77'],
['169.136.241.78'],
['169.136.241.79'],
['169.136.241.81'],
['169.136.241.82'],
['169.136.241.85']]]

-- Paul
 
P

Prabhu Gurumurthy

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Paul said:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

All,

I have the following lines that I would like to parse in python using
pyparsing, but have some problems forming the grammar.

Line in file:
table <ALINK> const { 207.135.103.128/26, 207.135.112.64/29 }
table <INTRANET> persist { ! 10.200.2/24, 10.200/22 }
table <RFC_1918> const { 192.168/16, ! 172.24.1/29, 172.16/12, 169.254/16 }
table <DIALER> persist { 10.202/22 }
table <RAVPN> const { 10.206/22 }
table <KS> const { \
10.205.1/24, \
169.136.241.68, \
169.136.241.70, \
169.136.241.71, \
169.136.241.72, \
169.136.241.75, \
169.136.241.76, \
169.136.241.77, \
169.136.241.78, \
169.136.241.79, \
169.136.241.81, \
169.136.241.82, \
169.136.241.85 }

I have the following grammar defn.

tableName = Word(alphanums + "-" + "_")
leftClose = Suppress("<")
rightClose = Suppress(">")
key = Suppress("table")
tableType = Regex("persist|const")
ip4Address = OneOrMore(Word(nums + "."))
ip4Network = Group(ip4Address + Optional(Word("/") +
OneOrMore(Word(nums))))
temp = ZeroOrMore("\\" + "\n")
tableList = OneOrMore(Optional("\\") |
ip4Network | ip4Address | Suppress(",") | Literal("!"))
leftParen = Suppress("{")
rightParen = Suppress("}")

table = key + leftClose + tableName + rightClose + tableType + \
leftParen + tableList + rightParen

I cannot seem to match sixth line in the file above, i.e table name with
KS, how do I form the grammar for it, BTW, I still cannot seem to ignore
comments using table.ignore(Literal("#") + restOfLine), I get a parse error.

Any help appreciated.
Thanks
Prabhu
Click to expand...

Prabhu -

This is a good start, but here are some suggestions:

1. ip4Address = OneOrMore(Word(nums + "."))

Word(nums+".") will read any contiguous set of characters in the
string nums+".", so OneOrMore is not necessary for reading in an
ip4Address. Just use:

ip4Address = Word(nums + ".")


2. ip4Network = Group(ip4Address + Optional(Word("/") +
OneOrMore(Word(nums))))

Same comment, OneOrMore is not needed for the added value to the
ip4Address:

ip4Network = Group(ip4Address + Optional(Word("/") + Word(nums))))


3. tableList = OneOrMore(Optional("\\") |
ip4Network | ip4Address | Suppress(",") |
Literal("!"))

The list of ip4Networks is just a comma-delimited list, with some
entries preceded with a '!' character. It is simpler to use
pyparsing's built-in helper, delimitedList, as in:

tableList = Group( delimitedList(Group("!"+ip4Network)|ip4Network) )


Yes, I know, you are saying, "but what about all those backslashes?"
The backslashes look like they are just there as line continuations.
We can define an ignore expression, so that the table expression, and
all of its contained expressions, will ignore '\' characters as line
continuations:

table.ignore( Literal("\\") + LineEnd() )

And I'm not sure why you had trouble with ignoring '#' + restOfLine,
it works fine in the program below.

If you make these changes, your program will look something like this:

tableName = Word(alphanums + "-" + "_")
leftClose = Suppress("<")
rightClose = Suppress(">")
key = Suppress("table")
tableType = Regex("persist|const")
ip4Address = Word(nums + ".")
ip4Network = Group(ip4Address + Optional(Word("/") + Word(nums)))
tableList = Group(delimitedList(Group("!"+ip4Network)|ip4Network))
leftParen = Suppress("{")
rightParen = Suppress("}")

table = key + leftClose + tableName + rightClose + tableType + \
leftParen + tableList + rightParen
table.ignore(Literal("\\") + LineEnd())
table.ignore(Literal("#") + restOfLine)

# parse the input line, and pprint the results
result = OneOrMore(table).parseString(line)
from pprint import pprint
pprint(result.asList())

Prints out:
['ALINK',
'const',
[['207.135.103.128', '/', '26'], ['207.135.112.64', '/', '29']],
'INTRANET',
'persist',
[['!', ['10.200.2', '/', '24']], ['10.200', '/', '22']],
'RFC_1918',
'const',
[['192.168', '/', '16'],
['!', ['172.24.1', '/', '29']],
['172.16', '/', '12'],
['169.254', '/', '16']],
'DIALER',
'persist',
[['10.202', '/', '22']],
'RAVPN',
'const',
[['10.206', '/', '22']],
'KS',
'const',
[['10.205.1', '/', '24'],
['169.136.241.68'],
['169.136.241.70'],
['169.136.241.71'],
['169.136.241.72'],
['169.136.241.75'],
['169.136.241.76'],
['169.136.241.77'],
['169.136.241.78'],
['169.136.241.79'],
['169.136.241.81'],
['169.136.241.82'],
['169.136.241.85']]]

-- Paul
Click to expand...

Awesome, thanks a lot will try it today and will let you know how it
proceeds.

thanks again.
Prabhu
- -
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.4-svn0 (GNU/Linux)
Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org

iD8DBQFHXWOQTkjpaeKzB9YRAq/aAJ9b0uocbP+1XxIVj4LgS76uFEuQHwCgxojY
zv05Raaj5McSEzDWXiSxf9c=
=MMFV
-----END PGP SIGNATURE-----
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Similar Threads

pyparsing problem 3
Pyparsing... 2
Pyparsing help 9
help with pyparsing 1
pyparsing 4
pyparsing and svg 2
Ann: Pyparsing 1.5.0 released 0
pyparsing with nested table 2

Members online

No members online now.
Total: 55 (members: 0, guests: 55)
Robots: 416

Forum statistics

Threads
473,982
Messages
2,570,190
Members
46,740
Latest member
AdolphBig6

Latest Threads

Top