pylha

A Python package to convert data files in SLHA and similar formats to Python objects, JSON, or YAML.

Motivation

In particle physics phenomenology, structured data like model parameters are frequently exchanged in a file format inspired by the SUSY Les Houches Accord, for instance

Block MODSEL		     # Select model
    1    1		     # sugra
Block MINPAR		     # Input parameters
    1   1.000000000e+02	     # m0
    2   2.500000000e+02	     # m12
    3   1.000000000e+01	     # tanb
    4   1.000000000e+00	     # sign(mu)
    5  -1.000000000e+02	     # A0

Other examples include the FLHA ("Flavour Les Houches Accord") and the input and outputs files formats of DSixTools and Rosetta.

While several well-tested parsers exist for the original SLHA format, most of these are not robust enough to treat the generalized formats. The purpose of pylha is to provide a simple low-level Python package that allows to import any file in a "LHA-like" format into a Python data structure and export it back to industry-standard exchange formats like JSON or YAML (or back to LHA format).

Usage

At the moment, pylha can only be used as a Python module (command line scripts might be added later). To install it, use

pip3 install pylha

The above example string can be converted to a JSON string using

import pylha
d = pylha.load(example_string)
pylha.dump(d, 'json')

Which will return

{
  "BLOCK": {
    "MODSEL": {
      "values": [[1, 1]]
    },
    "MINPAR": {
      "values": [[1, 100.0], [2, 250.0], [3, 10.0], [4, 1.0], [5, -100.0]]
    }
  }
}