Source code for matchms.importing.load_from_json

import ast
import json
import logging
from typing import List, Union
import numpy
from ..Spectrum import Spectrum

logger = logging.getLogger("matchms")

[docs]def load_from_json(filename: str, metadata_harmonization: bool = True) -> List[Spectrum]: """Load spectrum(s) from json file. JSON document formatted like the `GNPS Spectra library <>`_. Spectrums with zero peaks will be skipped. Example: .. code-block:: python from matchms.importing import load_from_json file_json = "gnps_testdata.json" spectrums = load_from_json(file_json) Parameters ---------- filename Provide filename for json file containing spectrum(s). metadata_harmonization : bool, optional Set to False if metadata harmonization to default keys is not desired. The default is True. """ with open(filename, 'rb') as fin: spectrums = [] for spectrum_dict in json.load(fin): spectrum = as_spectrum(spectrum_dict, metadata_harmonization=metadata_harmonization) if spectrum is not None: spectrums.append(spectrum) return spectrums
[docs]def as_spectrum(dct: dict, metadata_harmonization: bool = True) -> Union[dict, Spectrum, None]: """A :py:func:`json.load` object_hook to convert dictionary shaped like spectrum into :py:class:`~matchms.Spectrum.Spectrum` object. Parameters ---------- dct Dictionary shaped like spectrum Returns ------- A Spectrum or None when no peaks where found. """ # Recognize Spectrum by peaks_json key if 'peaks_json' in dct: return dict2spectrum(dct, metadata_harmonization=metadata_harmonization) return None
[docs]def dict2spectrum(spectrum_dict: dict, metadata_harmonization: bool) -> Union[Spectrum, None]: """Convert dictionary to a :py:class:`~matchms.Spectrum.Spectrum` object. Parameters ---------- spectrum_dict Dictionary shaped like a single JSON object from the `GNPS Spectra library <>`_ Returns ------- A Spectrum or None when no peaks where found. """ not_metadata_fields = ["peaks_json"] parse_fieldnames = dict(inchi_aux="inchiaux", ion_mode="ionmode") def get_peaks_list(spectrum_dict, fieldname): peaks_list = spectrum_dict.get(fieldname) if isinstance(peaks_list, list): return peaks_list # Handle peaks list when stored as string if isinstance(peaks_list, str): return ast.literal_eval(peaks_list) return [] def parse_fieldname(key): """Add options to read GNPS style json files.""" key_parsed = key.lower() key_parsed = parse_fieldnames.get(key_parsed, key_parsed) return key_parsed metadata_dict = {parse_fieldname(key): spectrum_dict[key] for key in spectrum_dict if key not in not_metadata_fields} peaks_list = get_peaks_list(spectrum_dict, "peaks_json") if len(peaks_list) > 0 and metadata_dict: mz = numpy.array(peaks_list)[:, 0] intensities = numpy.array(peaks_list)[:, 1] # Sort by mz (if not sorted already) if not numpy.all(mz[:-1] <= mz[1:]): idx_sorted = numpy.argsort(mz) mz = mz[idx_sorted] intensities = intensities[idx_sorted] return Spectrum(mz=mz, intensities=intensities, metadata=metadata_dict, metadata_harmonization=metadata_harmonization)"Empty spectrum found (no peaks in 'peaks_json'). Will not be imported.") return None