从此文本文件中提取值的 Pythonic 方法

rob*_*ntw 5 python text idioms

我有一个来自遗留软件的输出文件,如下所示。我想从中提取值,例如,我可以设置一个名为direct_solar_irradianceto648.957target ground pressureto的变量1013.00

到目前为止,我一直在提取单独的行并像下面这样处理它们(针对我想要提取的不同值重复多次):

values = lines[97].split()
self.irradiance_direct, self.irradiance_diffuse, self.irradiance_env = values
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但是,我现在发现在选择某些参数时会在输出中间添加额外的行。这当然意味着第 97 行将不再包含我需要的值。

鉴于在某些情况下可能会在输出中添加额外的行,是否有一种很好的 Pythonic 方法来提取这些值?我想我需要在文件中搜索已知的文本片段,然后提取它们引用的数字,但我能想到的唯一方法是非常笨拙。

所以:

  1. 有没有一种很好的 Pythonic 方法来搜索这些字符串并提取我想要的值?

  2. 如果没有,是否有其他方法可以明智地做到这一点?(例如,某种我一无所知的酷文本文件解析库)。

    ******************************* 6sV version 1.0B ******************************
    *                                                                             *
    *                       geometrical conditions identity                       *
    *                       -------------------------------                       *
    *                       user defined conditions                               *
    *                                                                             *
    *   month: 14 day :   1                                                       *
    *   solar zenith angle:   10.00 deg  solar azimuthal angle:       20.00 deg   *
    *   view zenith angle:    30.00 deg  view azimuthal angle:        40.00 deg   *
    *   scattering angle:    159.14 deg  azimuthal angle difference:  20.00 deg   *
    *                                                                             *
    *                       atmospheric model description                         *
    *                       -----------------------------                         *
    *           atmospheric model identity :                                      *
    *               midlatitude summer  (uh2o=2.93g/cm2,uo3=.319cm-atm)           *
    *           aerosols type identity :                                          *
    *               Maritime aerosol model                                        *
    *           optical condition identity :                                      *
    *               visibility :  8.49 km  opt. thick. 550 nm :  0.5000           *
    *                                                                             *
    *                       spectral condition                                    *
    *                       ------------------                                    *
    *            monochromatic calculation at wl 0.400 micron                     *
    *                                                                             *
    *                       Surface polarization parameters                       *
    *                       ----------------------------------                    *
    *                                                                             *
    *                                                                             *
    * Surface Polarization Q,U,Rop,Chi    0.00000  0.00000  0.00000     0.00      *
    *                                                                             *
    *                                                                             *
    *                       target type                                           *
    *                       -----------                                           *
    *           homogeneous ground                                                *
    *             monochromatic reflectance  1.000                                *
    *                                                                             *
    *                       target elevation description                          *
    *                       ----------------------------                          *
    *           ground pressure  [mb] 1013.00                                     *
    *           ground altitude  [km] 0.000                                       *
    *                                                                             *
    *                       plane simulation description                          *
    *                       ----------------------------                          *
    *           plane  pressure          [mb] 1013.00                             *
    *           plane  altitude absolute [km]  0.000                              *
    *                atmosphere under plane description:                          *
    *                ozone content             0.000                              *
    *                h2o   content             0.000                              *
    *               aerosol opt. thick. 550nm  0.000                              *
    *                                                                             *
    *                        atmospheric correction activated                     *
    *                        --------------------------------                     *
    *                        BRDF coupling correction                             *
    *           input apparent reflectance :  0.500                               *
    *                                                                             *
    *******************************************************************************
    
    
    
    *******************************************************************************
    *                                                                             *
    *                         integrated values of  :                             *
    *                         --------------------                                *
    *                                                                             *
    *       apparent reflectance  1.1287696  appar. rad.(w/m2/sr/mic)  588.646    *
    *                   total gaseous transmittance  1.000                        *
    *                                                                             *
    *******************************************************************************
    *                                                                             *
    *                         coupling aerosol -wv  :                             *
    *                         --------------------                                *
    *           wv above aerosol :   1.129     wv mixed with aerosol :   1.129    *
    *                       wv under aerosol :   1.129                            *
    *******************************************************************************
    *                                                                             *
    *                         integrated values of  :                             *
    *                         --------------------                                *
    *                                                                             *
    *       app. polarized refl.  0.0000    app. pol. rad. (w/m2/sr/mic)    0.000 *
    *             direction of the plane of polarization  0.00                    *
    *                   total polarization ratio     0.000                        *
    *                                                                             *
    *******************************************************************************
    *                                                                             *
    *                         int. normalized  values  of  :                      *
    *                         ---------------------------                         *
    *                      % of irradiance at ground level                        *
    *     % of direct  irr.    % of diffuse irr.    % of enviro. irr              *
    *               0.351               0.354               0.295                 *
    *                       reflectance at satellite level                        *
    *     atm. intrin. ref.   background  ref.  pixel  reflectance                *
    *               0.000               0.000               1.129                 *
    *                                                                             *
    *                         int. absolute values of                             *
    *                         -----------------------                             *
    *                      irr. at ground level (w/m2/mic)                        *
    *     direct solar irr.    atm. diffuse irr.    environment  irr              *
    *             648.957             655.412             544.918                 *
    *                      rad at satel. level (w/m2/sr/mic)                      *
    *     atm. intrin. rad.    background  rad.    pixel  radiance                *
    *               0.000               0.000             588.646                 *
    *                                                                             *
    *                                                                             *
    *                      sol. spect (in w/m2/mic)                               *
    *                                1663.594                                     *
    *                                                                             *
    *******************************************************************************
    
    
    
    
    
    *******************************************************************************
    *                                                                             *
    *                          integrated values of  :                            *
    *                          --------------------                               *
    *                                                                             *
    *                             downward        upward          total           *
    *      global gas. trans. :     1.00000        1.00000        1.00000         *
    *      water   "     "    :     1.00000        1.00000        1.00000         *
    *      ozone   "     "    :     1.00000        1.00000        1.00000         *
    *      co2     "     "    :     1.00000        1.00000        1.00000         *
    *      oxyg    "     "    :     1.00000        1.00000        1.00000         *
    *      no2     "     "    :     1.00000        1.00000        1.00000         *
    *      ch4     "     "    :     1.00000        1.00000        1.00000         *
    *      co      "     "    :     1.00000        1.00000        1.00000         *
    *                                                                             *
    *                                                                             *
    *      rayl.  sca. trans. :     0.84422        1.00000        0.84422         *
    *      aeros. sca.   "    :     0.94572        1.00000        0.94572         *
    *      total  sca.   "    :     0.79616        1.00000        0.79616         *
    *                                                                             *
    *                                                                             *
    *                                                                             *
    *                             rayleigh       aerosols         total           *
    *                                                                             *
    *      spherical albedo   :     0.23410        0.12354        0.29466         *
    *      optical depth total:     0.36193        0.55006        0.91199         *
    *      optical depth plane:     0.00000        0.00000        0.00000         *
    *      reflectance I      :     0.00000        0.00000        0.00000         *
    *      reflectance Q      :     0.00000        0.00000        0.00000         *
    *      reflectance U      :     0.00000        0.00000        0.00000         *
    *      polarized reflect. :     0.00000        0.00000        0.00000         *
    *      degree of polar.   :         nan           0.00            nan         *
    *      dir. plane polar.  :      -45.00         -45.00         -45.00         *
    *      phase function I   :     1.38819        0.27621        0.71751         *
    *      phase function Q   :    -0.09117       -0.00856       -0.04134         *
    *      phase function U   :    -1.34383        0.02142       -0.52039         *
    *      primary deg. of pol:    -0.06567       -0.03099       -0.05762         *
    *      sing. scat. albedo :     1.00000        0.98774        0.99261         *
    *                                                                             *
    *                                                                             *
    *******************************************************************************
    *******************************************************************************
    
    
    
    *******************************************************************************
    *                        atmospheric correction result                        *
    *                        -----------------------------                        *
    *       input apparent reflectance            :    0.500                      *
    *       measured radiance [w/m2/sr/mic]       :  260.747                      *
    *       atmospherically corrected reflectance                                 *
    *       Lambertian case :      0.52995                                        *
    *       BRDF       case :      0.52995                                        *
    *       coefficients xa xb xc                 :  0.00241  0.00000  0.29466    *
    *       y=xa*(measured radiance)-xb;  acr=y/(1.+xc*y)                         *
    
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Fre*_*ihl 2

您可以使用自己的迷你语言,即自动提取。我执行了以下操作来自动解析专有程序输出

# will match in the order written here
tokens = ["num_ref_frames", "Max QP", "Min QP", "Avg QP", "I4x4",
          "I16x16", "SkipZero", "SkipMV", "16x16", "16x8", "8x16",
          "8x8", "8x4", "4x8", "4x4"]

special = ["Quarterpel MVs"]

# this dictionary (hash-table) contains the search string from tokens array
# as well as an array where the first element is the field to extract to
# create matrix array. e.g. 0 = 1st field, 1 = 2nd field, 3 = 3rd field etc.
dict = {tokens[0]:  [1], tokens[1]:  [1], tokens[2]:  [1], tokens[3]:  [1],
        tokens[4]:  [2], tokens[5]:  [2], tokens[6]:  [2], tokens[7]:  [2],
        tokens[8]:  [2], tokens[9]:  [2], tokens[10]: [2], tokens[11]: [2],
        tokens[12]: [2], tokens[13]: [2], tokens[14]: [2],}
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然后我简单地循环输入,并针对每一行检查token;的内容。如果发现匹配,我根据字典条目进行分割以提取正确的字段。

special上面是处理一个需要从多行读取的特殊变量。

更新

克隆git://gist.github.com/1037403.git以获取代码的副本

usage:
./parser.py all_dec.txt
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希望能帮助到你!