networkconfparse 0.2.0

Parse whitespace-based network configuration into a tree of parent/child relationships.

networkconfparse

networkconfparse is a library that parses the whitespace-indented configuration of network infrastructure (Cisco IOS, IOS XE, IOS XR, and NX-OS) into a queryable tree of native Python objects.

Why networkconfparse?

• Standalone - No runtime dependencies. Install and use it in any Python project.
• Network-OS agnostic - Hierarchy is inferred from relative indentation, so IOS (one space), NX-OS (two spaces), and inconsistent indentation are all handled without per-platform rules.
• Queryable - A small, composable API to find configuration objects by regex, by predicate, or by their parent/child relationships.
• Handles the awkward parts - Transparently skips ! comment and delimiter lines and captures multiline banner blocks and inline certificate data as opaque bodies, rather than mistaking them for configuration.
• Typed and well-tested - Fully type-hinted with a comprehensive test suite.

Installation

networkconfparse can be quickly and easily installed with uv as shown below:

uv add networkconfparse

Or, if you prefer good old-fashioned pip, you can do so as shown below:

pip install networkconfparse

Quick Examples

Parsing a Configuration

Call parse() with the configuration text. It returns a Config whose top-level lines each carry their indented children as a tree of ConfigNode objects. Comment/delimiter lines (!) are dropped automatically.

import networkconfparse

config = networkconfparse.parse("""
interface GigabitEthernet0/0
 ip address 10.0.0.1 255.255.255.0
 no shutdown
!
interface GigabitEthernet0/1
 shutdown
!
""")

for interface in config.find(r"^interface "):
    print(interface.text, "->", [child.text for child in interface.children])

Prints:

interface GigabitEthernet0/0 -> ['ip address 10.0.0.1 255.255.255.0', 'no shutdown']
interface GigabitEthernet0/1 -> ['shutdown']

Querying the Tree

find() searches the entire tree and accepts a regular expression, a where predicate, or both. find_child()/has_child() look only at a node's immediate children, and find_one() returns the first match. Every node also exposes path, ancestors, descendants, and root for navigation.

# Interfaces that have an IP address configured anywhere beneath them.
configured = config.find(r"^interface ", where=lambda node: node.has_child(r"^ip address "))

# The first matching line, or None.
mgmt = config.find_one(r"^ip address 10\.0\.0\.1")

# Where does that line live in the hierarchy?
print(mgmt.path)
# ['interface GigabitEthernet0/0', 'ip address 10.0.0.1 255.255.255.0']

Relationship Helpers

For the common cases, dedicated helpers read more clearly than a hand-written predicate. Each accepts a single regex or a list (combined with AND), and they are simply convenience wrappers around find():

# Parents matching "interface" that have BOTH children as direct children.
config.find_with_child(r"^interface ", [r"^ip address ", r"^no shutdown"])

# Parents that have a matching line anywhere below them (not just direct children).
config.find_with_descendant(r"^router bgp ", r"neighbor")

# Lines whose direct parent matches.
config.find_with_parent(r"^neighbor ", r"^address-family ipv4")

# Lines with a matching ancestor anywhere above (or a consecutive chain with adjacent=True).
config.find_with_ancestor(r"^neighbor ", [r"^router bgp ", r"^address-family ipv4"])

Each helper has a find_without_* counterpart for the equally common absence questions ("interfaces without an ip address"). Given a list they apply a "none present" (NOR) rule, returning nodes where none of the patterns are found:

# Interfaces with neither an `ip address` nor a `shutdown` line.
config.find_without_child(r"^interface ", [r"^ip address ", r"^shutdown"])

These compose naturally for SDK-style questions. For example, "find every ACL that does not end with an explicit deny":

acls = config.find(r"^ip access-list ")
missing_deny = [
    acl for acl in acls
    if not acl.children or not acl.children[-1].matches(r"^deny ")
]

Documentation

Full documentation is available at chartinolabs.github.io/networkconfparse.

• Changelog - Release history built from changelog fragments
• Changelog Fragments Guide - How to add release-note fragments
• Releasing - How to compile release notes and cut a release

Acknowledgments

• Conceptual inspiration - The idea of modeling a network device configuration as a queryable parent/child tree owes a great deal to Mike Pennington's work on CiscoConfParse and CiscoConfParse2. networkconfparse is an independent, clean-room implementation; it is not affiliated with, derived from, or endorsed by those projects.

Status

Early development. The API is still evolving and may change as the library matures.