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


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).


At the moment, pylha can only be used as a Python module (command line scripts will 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]]