将带有结构的 .mat 文件提取到 Python 中答案

【问题标题】：Extracting .mat files with structs into Python将带有结构的 .mat 文件提取到 Python 中
【发布时间】：2020-11-09 17:22:19
【问题描述】：

我是 python 新手，在提取文件数据时遇到困难。所以我有一个 .mat 文件，它在 Matlab 中有以下输出：

d= open('tesla.mat')

d =

带有字段的结构：

diga: [1×1 struct]

d.diga.daten

ans =

带有字段的结构：

       Programmdauer: [1×78 double]
              SOCVec: [1×78 double]
            Spannung: [1×78 double]
         SpannungVec: [1×78 double]
               Strom: [1×78 double]
            StromVec: [1×78 double]
       TemperaturVec: [1×78 double]
   ThermischLeistung: [1×78 double]
ThermischLeistungVec: [1×78 double]

d.diga.daten.Spannung

ans =

第 1 至 20 列

4.0544    4.2100    4.2133    4.2149    4.2159    4.2168    4.2175    4.2181    4.2186    4.2191    4.0332    4.0265    4.0247    4.0235    4.0227    4.0223    4.0219    4.0217    4.0215    4.0213

第 21 到 40 列

4.0211    4.0210    4.0208    4.0552    4.0559    4.0561    4.0563    4.0564    4.0564    4.0564    4.0564    4.0564    4.0564    4.0564    4.0563    4.0563    4.0563    4.0563    4.0563    4.0563

第 41 到 60 列

4.0562    4.0562    4.0562    4.0562    4.0562    4.0562    4.0561    4.0561    4.0561    4.0561    4.0561    4.0561    4.0561    4.0561    4.0561    4.0560    4.0560    4.0560    4.0560    4.0560

第 61 到 78 列

4.0560    4.0560    4.0560    4.0560    4.0560    4.0560    4.0559    4.0559    4.0559    4.0559    4.0559    4.0559    4.0559    4.0559    4.0559    4.0559    4.0559    4.0559

我想在 python 中解析这些数据并提取这个特定的变量，例如 Spannung data 。 python中的输出如下：

{'__header__': b'MATLAB 5.0 MAT-file, Platform: x86_64-pc-linux-gnu, Created by: libmatio v1.5.9 on Mon Jul  6 20:29:51 2020', '__version__': '1.0', '__globals__': [], 'diga': array([[(array([[(array([[0.        , 0.10464944, 0.21018082, 0.31937647, 0.42176473,
    0.53570583, 0.6428233 , 0.74994078, 0.85705826, 0.96417574,
    1.0681423 , 1.17389392, 1.28139943, 1.40048611, 1.52559419,
    1.64743952, 1.76928485, 1.89113018, 2.        , 2.12290829,
    2.24581658, 2.36872488, 2.49163317, 2.59454399, 2.69687044,
    2.81347033, 2.93308651, 3.05714129, 3.17464839, 3.3055228 ,
    3.45267061, 3.58849168, 3.77533445, 3.88176795, 3.998157  ,
    4.19674602, 4.34787781, 4.5       , 4.69631901, 4.83781901,
    4.99708256, 5.20507697, 5.37073747, 5.5       , 5.6080527 ,
    5.78533992, 5.95166902, 6.09878942, 6.28218433, 6.4540618 ,
    6.59066557, 6.69357254, 6.8539116 , 6.95566133, 7.08274939,
    7.19399435, 7.3374617 , 7.44876399, 7.58496883, 7.70381522,
    7.83578215, 7.94780886, 8.08803463, 8.19780798, 8.34935696,
    8.45694731, 8.58460976, 8.69666891, 8.83509531, 8.94704739,
    9.08658847, 9.20783487, 9.33469661, 9.44355668, 9.59016133,
    9.6962619 , 9.85349258, 9.95928693]]), array([[88.3       , 88.30430713, 88.30865056, 88.3131448 , 88.31735886,
    88.32204841, 88.32645712, 88.33086583, 88.33527453, 88.33968324,
    88.34053444, 88.33956722, 88.33858396, 88.33749478, 88.33635052,
    88.3352361 , 88.33412169, 88.33300727, 88.33201153, 88.33088739,
    88.32976326, 88.32863912, 88.32751498, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846, 88.32743846, 88.32743846,
    88.32743846, 88.32743846, 88.32743846]]), array([[4.05436068, 4.21002405, 4.21327229, 4.21486158, 4.21591229,
    4.2168056 , 4.21748722, 4.21807606, 4.21860772, 4.21910362,
    4.03324528, 4.0265357 , 4.02467542, 4.02350034, 4.02273807,
    4.02225604, 4.02191832, 4.02166347, 4.02147603, 4.02129491,
    4.02113115, 4.020979  , 4.02083454, 4.05516985, 4.05587307,
    4.05613862, 4.05627884, 4.05635271, 4.05638517, 4.0563976 ,
    4.0563957 , 4.05638637, 4.05636811, 4.05635644, 4.05634327,
    4.05632056, 4.05630343, 4.05628649, 4.05626516, 4.05625018,
    4.05623371, 4.05621284, 4.0561967 , 4.05618439, 4.0561743 ,
    4.05615809, 4.05614328, 4.05613048, 4.0561149 , 4.05610068,
    4.05608961, 4.05608141, 4.05606887, 4.05606105, 4.05605142,
    4.05604313, 4.05603261, 4.05602458, 4.05601491, 4.0560066 ,
    4.05599751, 4.05598991, 4.05598053, 4.0559733 , 4.05596346,
    4.05595658, 4.05594852, 4.05594153, 4.05593303, 4.05592624,
    4.05591789, 4.05591073, 4.05590333, 4.05589706, 4.05588872,
    4.05588277, 4.05587405, 4.05586825]]), array([[4.05436068, 4.21002405, 4.21327229, 4.21486158, 4.21591229,
    4.2168056 , 4.21748722, 4.21807606, 4.21860772, 4.21910362,
    4.03324528, 4.0265357 , 4.02467542, 4.02350034, 4.02273807,
    4.02225604, 4.02191832, 4.02166347, 4.02147603, 4.02129491,
    4.02113115, 4.020979  , 4.02083454, 4.05516985, 4.05587307,
    4.05613862, 4.05627884, 4.05635271, 4.05638517, 4.0563976 ,
    4.0563957 , 4.05638637, 4.05636811, 4.05635644, 4.05634327,
    4.05632056, 4.05630343, 4.05628649, 4.05626516, 4.05625018,
    4.05623371, 4.05621284, 4.0561967 , 4.05618439, 4.0561743 ,
    4.05615809, 4.05614328, 4.05613048, 4.0561149 , 4.05610068,
    4.05608961, 4.05608141, 4.05606887, 4.05606105, 4.05605142,
    4.05604313, 4.05603261, 4.05602458, 4.05601491, 4.0560066 ,
    4.05599751, 4.05598991, 4.05598053, 4.0559733 , 4.05596346,
    4.05595658, 4.05594852, 4.05594153, 4.05593303, 4.05592624,
    4.05591789, 4.05591073, 4.05590333, 4.05589706, 4.05588872,
    4.05588277, 4.05587405, 4.05586825]]), array([[ 0. ,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5, -1. ,
    -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. ,
    -1. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ]]), array([[ 0. ,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5,  4.5, -1. ,
    -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. , -1. ,
    -1. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,  0. ,
     0. ]]), array([[25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25.,
    25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25.,
    25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25.,
    25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25.,
    25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25.,
    25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25., 25.]]), array([[0.00000000e+00, 6.85992309e-01, 7.03449743e-01, 7.10867829e-01,
    7.15615588e-01, 7.19174707e-01, 7.21389575e-01, 7.22912024e-01,
    7.24007563e-01, 7.24847258e-01, 4.45033989e-02, 3.85461248e-02,
    3.58360767e-02, 3.53935152e-02, 3.56460808e-02, 3.59131697e-02,
    3.60769536e-02, 3.61500744e-02, 3.61654153e-02, 3.61491829e-02,
    3.61153062e-02, 3.60739446e-02, 3.60309650e-02, 9.69429070e-04,
    5.35032457e-04, 3.58732548e-04, 2.92579042e-04, 2.64021521e-04,
    2.49466440e-04, 2.38203495e-04, 2.27951943e-04, 2.19594624e-04,
    2.09204995e-04, 2.03745280e-04, 1.98105959e-04, 1.89197221e-04,
    1.82955847e-04, 1.77092643e-04, 1.70083570e-04, 1.65383061e-04,
    1.60410350e-04, 1.54374091e-04, 1.49900760e-04, 1.46597195e-04,
    1.43952210e-04, 1.39825410e-04, 1.36175399e-04, 1.33110819e-04,
    1.29488217e-04, 1.26275854e-04, 1.23838901e-04, 1.22066587e-04,
    1.19407152e-04, 1.17780340e-04, 1.15810875e-04, 1.14141001e-04,
    1.12057839e-04, 1.10493479e-04, 1.08637272e-04, 1.07067274e-04,
    1.05375319e-04, 1.03979386e-04, 1.02281688e-04, 1.00989373e-04,
    9.92555314e-05, 9.80583899e-05, 9.66725802e-05, 9.54858692e-05,
    9.40565860e-05, 9.29290483e-05, 9.15576202e-05, 9.03953350e-05,
    8.92071874e-05, 8.82095618e-05, 8.68967397e-05, 8.59677815e-05,
    8.46224613e-05, 8.37375088e-05]]), array([[0.00000000e+00, 6.85992309e-01, 7.03449743e-01, 7.10867829e-01,
    7.15615588e-01, 7.19174707e-01, 7.21389575e-01, 7.22912024e-01,
    7.24007563e-01, 7.24847258e-01, 4.45033989e-02, 3.85461248e-02,
    3.58360767e-02, 3.53935152e-02, 3.56460808e-02, 3.59131697e-02,
    3.60769536e-02, 3.61500744e-02, 3.61654153e-02, 3.61491829e-02,
    3.61153062e-02, 3.60739446e-02, 3.60309650e-02, 9.69429070e-04,
    5.35032457e-04, 3.58732548e-04, 2.92579042e-04, 2.64021521e-04,
    2.49466440e-04, 2.38203495e-04, 2.27951943e-04, 2.19594624e-04,
    2.09204995e-04, 2.03745280e-04, 1.98105959e-04, 1.89197221e-04,
    1.82955847e-04, 1.77092643e-04, 1.70083570e-04, 1.65383061e-04,
    1.60410350e-04, 1.54374091e-04, 1.49900760e-04, 1.46597195e-04,
    1.43952210e-04, 1.39825410e-04, 1.36175399e-04, 1.33110819e-04,
    1.29488217e-04, 1.26275854e-04, 1.23838901e-04, 1.22066587e-04,
    1.19407152e-04, 1.17780340e-04, 1.15810875e-04, 1.14141001e-04,
    1.12057839e-04, 1.10493479e-04, 1.08637272e-04, 1.07067274e-04,
    1.05375319e-04, 1.03979386e-04, 1.02281688e-04, 1.00989373e-04,
    9.92555314e-05, 9.80583899e-05, 9.66725802e-05, 9.54858692e-05,
    9.40565860e-05, 9.29290483e-05, 9.15576202e-05, 9.03953350e-05,
    8.92071874e-05, 8.82095618e-05, 8.68967397e-05, 8.59677815e-05,
    8.46224613e-05, 8.37375088e-05]]))]],
  dtype=[('Programmdauer', 'O'), ('SOCVec', 'O'), ('Spannung', 'O'), ('SpannungVec', 'O'), ('Strom', 'O'), ('StromVec', 'O'), ('TemperaturVec', 'O'), ('ThermischLeistung', 'O'), ('ThermischLeistungVec', 'O')]),)]],
  dtype=[('daten', 'O')])}

用 python 编写来提取特定数组数据的代码是什么。

【问题讨论】：

标签： python matlab dictionary multidimensional-array

【解决方案1】：

好的，我正在添加第二个答案，其中包含一个通用的小函数，该函数可以提取内部包含任何类型字段的数据 mat 文件，供将来可能需要它的人使用（甚至对我自己来说，我正在处理这个问题经常和每次我构建一个临时解决方案......）。

这个函数应该能够接受任何带有结构和嵌套结构的mat文件，并返回一个字典：

import scipy.io as sio

def load_from_mat(filename=None, data={}, loaded=None):
    if filename:
        vrs = sio.whosmat(filename)
        name = vrs[0][0]
        loaded = sio.loadmat(filename,struct_as_record=True)
        loaded = loaded[name]
    whats_inside = loaded.dtype.fields
    fields = list(whats_inside.keys())
    for field in fields:
        if len(loaded[0,0][field].dtype) > 0: # it's a struct
            data[field] = {}
            data[field] = load_from_mat(data=data[field], loaded=loaded[0,0][field])
        else: # it's a variable
            data[field] = loaded[0,0][field]
    return data

# and then just call the function
my_file = r"C:\Users\.......\data.mat"
data = load_from_mat(filename=my_file) # Don't worry about the other input vars (data, loaded), there are used in the recursion.

【讨论】：

【解决方案2】：

将 matlab 结构加载到 python 中有点麻烦，但是 scipy.io.loadmat 方法可以通过一些探索来完成。

查看 scipy.io.loadmat 的帮助。他们解释了它是如何工作的。

从加载文件开始：

import scipy.io as sio
my_struct = sio.loadmat(file_name)

然后，从dict中获取数据：

my_struct.keys() # this will show you the var name of your data, in your case diga (if I understand correctly)
data = my_struct["diga"]

现在，对于每一级嵌套结构，您可以使用 .dtype 查看内部的下一个结构，然后提取数据：

data.dtype
data[0,0]["daten"]

然后：

data[0,0,]["daten"][0,0]["Spannung"]

** 我可能错过了你的结构中的一个关卡，试试看它是否不完全适合你的结构。

【讨论】：

非常感谢...我得到了我想要的输出:)