nwdiag

3.0.0 verified Fri May 01 auth: no python

A simple text-to-image diagram generator for network diagrams, part of the blockdiag suite. Current version 3.0.0 supports Python >=3.7. Maintained irregularly.

pip install nwdiag

Common errors

error ImportError: cannot import name 'nwdiag' from 'nwdiag' ↓

cause Trying to import the submodule as 'from nwdiag import nwdiag' instead of 'import nwdiag'.

fix

Use 'import nwdiag' and then call nwdiag.command() or other functions.

error AttributeError: module 'nwdiag' has no attribute 'command' ↓

cause Installed a different package named nwdiag (e.g., from a third-party) or used an older version where the API was different.

fix

Uninstall any conflicting package and install the official nwdiag: pip install --upgrade nwdiag

error Parse error: syntax error, unexpected 'network' ↓

cause Missing semicolon after closing brace of a network block, or incorrect nesting of networks.

fix

Check that every block ends with a semicolon. Example: 'network dmz { ... };' not 'network dmz { ... }'

Warnings

gotcha nwdiag command line tool uses a different syntax than the Python API. The Python API expects a list of arguments similar to sys.argv, not the string directly. ↓

fix Use nwdiag.command(['-o', 'out.png', '-']) with stdin pipe, or nwdiag.command(['-o', 'out.png', 'diag.diag'])

deprecated The blockdiag suite is no longer actively maintained; issues and PRs may go unanswered. ↓

fix Consider alternatives like diagrams (https://github.com/mingrammer/diagrams) for active development.

gotcha The .diag file format uses semicolons at the end of definitions; missing semicolons cause parse errors with unhelpful messages. ↓

fix Ensure every bracket block ends with a semicolon, e.g., 'network name { ... };'

Imports

nwdiag
wrong
```
from nwdiag import nwdiag
```
correct
```
import nwdiag
```
The package top-level is the module; use import nwdiag then call nwdiag.command()
parser
wrong
```
import parser
```
correct
```
from nwdiag import parser
```
nwdiag.parser is the correct submodule, not the standard library parser

Quickstart

Generates a network diagram from a DOT-like text description.

import nwdiag

# Create a simple network diagram
nwdiag.command(['-o', 'output.png', '-']).stdout.write("""
nwdiag {
  network dmz {
    address = "192.168.1.0/24"

    web01 [address = "192.168.1.1"];
    web02 [address = "192.168.1.2"];
  }
  network internal {
    address = "10.0.0.0/8";

    db01 [address = "10.0.0.1"];
    db02 [address = "10.0.0.2"];
  }
}
""")