NTC Templates

Warnings

• breaking Version 9.0.0 introduced breaking changes. Users upgrading from previous major versions, especially those with custom templates or relying on specific output field names, should consult the official release notes for migration steps.
  Fix: Review the official release notes (e.g., `https://ntc-templates.readthedocs.io/en/latest/admin/release_notes/version_9.0/`) to understand specific breaking changes and update your code/templates accordingly. This may involve changes to expected dictionary keys due to a move towards a common data model.
• gotcha A common 'Cannot import name clitable from textfsm' error occurs due to an incompatibility between `ntc-templates` and certain `textfsm` PyPI distributions. This is often seen when `textfsm` is not explicitly pinned to a compatible version.
  Fix: Ensure `textfsm` is installed at version `1.1.0` using `pip install textfsm==1.1.0` before installing or using `ntc-templates`.
• gotcha NTC Templates rely on TextFSM, which uses regular expressions. If the raw CLI output from a network device changes format in a way not anticipated by the template, parsing may fail or produce incomplete/incorrect data. Templates do not guarantee to capture all possible data fields.
  Fix: Always implement error handling around `parse_output` calls. Validate the parsed output before using it in automation. If a template fails or misses data, consider contributing a fix or creating a custom template.
• deprecated Older versions of `ntc-templates` used `.template` for TextFSM template files and `.parsed` for expected output files. These extensions have been updated to `.textfsm` and `.yml` respectively.
  Fix: If maintaining custom TextFSM templates, rename your template files from `.template` to `.textfsm` and your parsed test files from `.parsed` to `.yml` for consistency and to leverage modern tooling like YAML linting.

Install

• pip install ntc-templates Install ntc-templates

Imports

• parse_output

  from ntc_templates.parse import parse_output

  The `parse_output` function resides within the `ntc_templates.parse` module, not directly under the top-level package.

Quickstart

This quickstart demonstrates how to parse raw CLI output using `ntc-templates`. It defines a sample `show version` output from a Cisco IOS device and uses `parse_output` with the corresponding platform and command to transform it into structured Python data (a list of dictionaries). Error handling is included as a best practice.

import os
from ntc_templates.parse import parse_output

# Example raw CLI output from a Cisco IOS device
raw_output = """
Cisco IOS Software, C800 Series Software (C800-UNIVERSALK9-M), Version 15.6(3)M5, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2017 by Cisco Systems, Inc.
Compiled Wed 27-Sep-17 12:00 by prod_rel_team

ROM: System Bootstrap, Version 15.5(3)M, RELEASE SOFTWARE (fc1)

Cisco C891F (1RU) processor (revision 1.0) with 1007616K/54272K bytes of memory.
Processor board ID FHK2126210F
10 Gigabit Ethernet interfaces
8 FastEthernet interfaces
2 Gigabit Ethernet interfaces
1 Virtual Private Network (VPN) Module
256K bytes of non-volatile configuration memory.
1024000K bytes of ATA System CompactFlash (Read/Write)

License Level: ipservices
License Type: Permanent
Next reload will be a ipservices license

Configuration register is 0x2102
"""

# Define the platform and command corresponding to an NTC template
platform = "cisco_ios"
command = "show version"

try:
    parsed_data = parse_output(platform=platform, command=command, data=raw_output)
    print(parsed_data)
except Exception as e:
    print(f"Error parsing output: {e}")

# Expected output is a list of dictionaries with parsed data
# Example of accessing some data (output structure depends on template):
# if parsed_data:
#     print(f"Software Version: {parsed_data[0].get('VERSION')}")
#     print(f"Platform: {parsed_data[0].get('HARDWARE')}")