Class CSVParser

python-package/compile/src/io/parser.hpp:18–53

namespace LightGBM {

class CSVParser: public Parser {
 public:
  explicit CSVParser(int label_idx, int total_columns)
    :label_idx_(label_idx), total_columns_(total_columns) {
  }
  inline void ParseOneLine(const char* str,
    std::vector<std::pair<int, double>>* out_features, double* out_label) const override {
    int idx = 0;
    double val = 0.0f;
    int offset = 0;
    *out_label = 0.0f;
    while (*str != '\0') {
      str = Common::Atof(str, &val);
      if (idx == label_idx_) {
        *out_label = val;
        offset = -1;
      } else if (std::fabs(val) > kZeroThreshold || std::isnan(val)) {
        out_features->emplace_back(idx + offset, val);
      }
      ++idx;
      if (*str == ',') {
        ++str;
      } else if (*str != '\0') {
        Log::Fatal("Input format error when parsing as CSV");
      }
    }
  }

  inline int NumFeatures() const override {
    return total_columns_ - (label_idx_ >= 0);
  }

 private:
  int label_idx_ = 0;
  int total_columns_ = -1;
};

class TSVParser: public Parser {
 public: