pgformat

Property Graph Exchange Format (PG) parser and serializer

This package implements parsers and serializers to for labeled property graphs in Property Graph Exchange Format.

Table of Contents

• Install
• Usage
• API
  • parseGraph
  • parseStatements
  • serializeGraph

Install

Requires Python 3.8 or above.

pip install pgformat

Usage

The package comes with a simple command line client to convert between serialization forms of Property Graph Exchange format and an API to be used in python code. The command line client by default reads PG Format and emits PG JSONL.

usage: pgformat [-h] [-t {ndjson,json,pg}] [source]

Parse and transform property graphs in PG Format.

positional arguments:
  source                input file (default: - for standard input)

options:
  -h, --help            show this help message and exit
  -t {ndjson,json,pg}, --to {ndjson,json,pg}
                        target format

The functionality is a subset of the pgraph command line tool written in NodeJS.

The command line client can also be called via python -m pgformat.

API

The package exports the functions parseGraph, parseStatements, and serializeGraph:

from pgformat import parseGraph, parseStatements, serializeGraph

statements = parseStatements("x\na -> b")   # list of statements
graph = parseGraph("a -> b")                # full graph

pg = serializeGraph(graph)                  # back to PG Format

The internal format of graphs and their statements is a data structure of plain lists and arrays for direct conversion to JSON. This may be changed in a future version.

parseGraph

parseGraph(str: str, sort=True, implicitNodes=True) -> dict

Parse a property graph given as string in PG Format. Returns a dict with keys nodes and edges (PG JSON format).

Optional parameter sort sorts nodes and edges by their identifier, and labels by their value. Optional parameter implicitNodes adds nodes for node identifiers referenced in edges only.

parseStatements

parseStatements(str: str, implicitNodes=True, mergeNodes=True, duplicatedEdges=False) -> list

Parse a list of statements given as string in PG Format. Returns a list of node and edge statements in order of appearance (PG JSON format).

Optional parameter mergeNodes applies merging of nodes with same identifiers. Optional parameter duplicatedEdges throws an exception if set to False.

serializeGraph

serializeGraph(graph: dict) -> str

Convert a property graph to PG Format.

License

Licensed under the MIT License.