chem.py 文件源码

def read_nox(ifile):
    _date = datetime.datetime.strptime(os.path.basename(ifile).split('_')[1], '%y%m%d')
    year = _date.year
    month = _date.month
    day = _date.day
    nox_dateparse = lambda x: pd.datetime(year, month, day) + \
          datetime.timedelta(seconds=int(float(float(x) % 1)*86400.))

    df_nox = pd.read_csv(ifile, parse_dates=[0], date_parser=nox_dateparse)
    df_nox = df_nox.set_index('TheTime')  # Setting index
    t = df_nox.index.values
    df_nox['timestamp'] = t.astype('datetime64[s]')  # Converting index data type
    df_nox = df_nox[['timestamp', 'no_conc', 'no2_conc', 'nox_conc']]
    df_nox[df_nox < 0] = np.nan
    return df_nox