Method LoadModelFromString

source/python.js:2998–3100

(model_str)

                }
            }
            LoadModelFromString(model_str) {
                const lines = model_str.split('\n');
                const signature = lines.shift() || '?';
                if (signature.trim() !== 'tree') {
                    throw new python.Error(`Invalid signature '${signature.trim()}'.`);
                }
                // GBDT::LoadModelFromString() in https://github.com/microsoft/LightGBM/blob/master/src/boosting/gbdt_model_text.cpp
                const key_vals = new Map();
                while (lines.length > 0 && !lines[0].startsWith('Tree=')) {
                    const cur_line = lines.shift().trim();
                    if (cur_line.length > 0) {
                        const strs = cur_line.split('=');
                        if (strs.length === 1) {
                            key_vals.set(strs[0], '');
                        } else if (strs.length === 2) {
                            key_vals.set(strs[0], strs[1]);
                        } else if (strs.length > 2) {
                            if (strs[0] === "feature_names") {
                                key_vals.set(strs[0], cur_line.substring("feature_names=".length));
                            } else if (strs[0] === 'monotone_constraints') {
                                key_vals.set(strs[0], cur_line.substring('monotone_constraints='.length));
                            } else {
                                throw new python.Error(`Wrong line: ${cur_line.substring(0, Math.min(128, cur_line.length))}`);
                            }
                        }
                    }
                }
                const atoi = (key, value) => {
                    if (key_vals.has(key)) {
                        return parseInt(key_vals.get(key), 10);
                    }
                    if (value !== undefined) {
                        return value;
                    }
                    throw new python.Error(`Model file does not specify ${key}.`);
                };
                const list = (key, size) => {
                    if (key_vals.has(key)) {
                        const value = key_vals.get(key).split(' ');
                        if (value.length !== size) {
                            throw new python.Error(`Wrong size of ${key}.`);
                        }
                        return value;
                    }
                    throw new python.Error(`Model file does not contain ${key}.`);
                };
                this.version = key_vals.get('version') || '';
                this.num_class = atoi('num_class');
                this.num_tree_per_iteration = atoi('num_tree_per_iteration', this.num_class);
                this.label_index = atoi('label_index');
                this.max_feature_idx = atoi('max_feature_idx');
                if (key_vals.has('average_output')) {
                    this.average_output = true;
                }
                this.feature_names = list('feature_names', this.max_feature_idx + 1);
                this.feature_infos = list('feature_infos', this.max_feature_idx + 1);
                if (key_vals.has('monotone_constraints')) {
                    this.monotone_constraints = list('monotone_constraints', this.max_feature_idx + 1);