python - 类型错误 : Object of type 'ndarray' is not JSON serializable

Question

knownEmbeddings = []
knownNames = []

for (i, imagePath) in enumerate(imagePaths):
    ## SOME CODE
    knownNames.append(name)
    knownEmbeddings.append(vec.flatten())


data = {"embeddings": knownEmbeddings, "names": knownNames}

f = open('file.json', "wb")
f.write(json.dumps(data, indent=4))
f.close()

数据如下所示:

{'embeddings': [array([ 2.23568859e-04, -4.08176295e-02, -1.56606492e-02, -1.40566211e-02,
        5.53448219e-04,  1.34807974e-01,  2.10583732e-02, -7.99260102e-03,
        8.04360434e-02,  2.51036473e-02, -2.45967298e-03,  8.73192959e-03,
        1.08047323e-02,  8.02712217e-02,  6.31465465e-02,  9.41963419e-02],
      dtype=float32), array([-5.54675907e-02,  1.19409459e-02, -3.03599555e-02, -2.86714472e-02,
        6.26528710e-02,  1.25348523e-01, -2.16291733e-02, -4.60545160e-02,
        6.25465512e-02, -7.61162862e-02,  4.28330414e-02,  8.57844874e-02,
        3.75184380e-02, -8.10878351e-02, -8.96525383e-02,  8.15552175e-02,
       -9.75750014e-02, -8.24848488e-02,  9.30746570e-02,  1.71318889e-01,
        1.00642473e-01,  5.39120510e-02,  1.12627009e-02,  1.40678780e-02,
       -4.41719554e-02,  1.03237763e-01,  4.38372791e-02,  7.53327608e-02],
      dtype=float32), array([-0.03736538, -0.0485549 , -0.0976112 , -0.06195155,  0.00269726,
        0.07389018, -0.07325964,  0.06653353, -0.04690087, -0.02606474,
        0.03597135,  0.06904668,  0.02198682, -0.06437466, -0.04554454,
        0.01083081, -0.06293067,  0.07047471,  0.02824293, -0.15522538,
       -0.01900602,  0.10689866, -0.07408814, -0.0419201 ,  0.10475922,
        0.04784475, -0.09085421, -0.20360689,  0.08321641,  0.08441921,
        0.01941148,  0.03566081, -0.05956643,  0.005247  , -0.03989819,
        0.02512971,  0.00458561,  0.13706829], dtype=float32), array([ 7.87236728e-03,  5.65276742e-02, -7.17918649e-02, -1.84332877e-02,
        1.28411269e-02,  2.85971135e-01,  3.13642109e-03,  2.48481780e-02,
       -9.48547944e-02,  2.89725009e-02,  4.33916636e-02,  9.01726633e-02,
        4.36290540e-02, -1.02897413e-01,  2.22285688e-02, -5.19381762e-02,
        1.52556881e-01, -1.25146270e-01,  3.18806712e-03, -2.51053665e-02,
       -4.36606398e-03,  7.19061792e-02,  4.66747172e-02,  8.13280419e-02],
      dtype=float32), array([ 0.09142991, -0.05100765, -0.09615178, -0.03553161,  0.11363017,
        0.19886988,  0.11280693,  0.0229619 , -0.0220201 , -0.01211688,
        0.07489388,  0.0802715 ,  0.16185616, -0.0904082 ,  0.0025941 ,
        0.12167819, -0.07357537, -0.01442344, -0.01343578,  0.16952834,
        0.03366659, -0.0534111 , -0.01595308,  0.15053654, -0.07398864,
        0.04694209, -0.06523879,  0.01342433], dtype=float32), array([-0.05331187,  0.08159426, -0.01742208,  0.00992642, -0.01155609,
        0.25759327, -0.00505029, -0.09290393,  0.01588799, -0.00478396,
        0.08572742, -0.05053008,  0.05197625,  0.1267016 ,  0.15398905,
        0.13668832, -0.13869229,  0.02502107, -0.04443422, -0.05987623,
        0.14948404,  0.03311499,  0.12621029], dtype=float32), array([ 0.1219558 , -0.0371135 , -0.13762642,  0.00431138,  0.20073804,
        0.09986125,  0.21617071,  0.02764285, -0.1352063 ,  0.02268699,
       -0.04734468,  0.10888206,  0.13558514, -0.00319178,  0.02979032,
        0.03558976, -0.07293532, -0.05351996, -0.02449711,  0.1459181 ,
       -0.00320001,  0.01020296, -0.05007216,  0.05868218, -0.03522768,
       -0.01064874, -0.0732395 , -0.05393502], dtype=float32), array([ 0.10833652,  0.08779355, -0.15162815, -0.03925862,  0.08713786,
        0.2850307 ,  0.13499181,  0.01792248, -0.1405847 ,  0.08626581,
        0.02001712, -0.06957201, -0.00727825,  0.01650161,  0.11886367,
        0.07897119, -0.14108546,  0.03840445,  0.05881708,  0.03361814,
       -0.0106756 , -0.04287936, -0.06621028], dtype=float32), array([ 4.90577929e-02,  9.13119391e-02, -2.76884548e-02, -5.19143604e-02,
        1.50506735e-01,  1.86451554e-01,  9.94046330e-02, -7.73873506e-03,
       -1.91362634e-01,  4.69892733e-02, -5.67045361e-02,  2.81608831e-02,
        5.74332848e-02, -9.09122005e-02,  1.46917075e-01,  4.63287433e-04,
        4.22818065e-02, -2.01395284e-02,  1.31114023e-02, -6.61114752e-02],
      dtype=float32), array([ 1.13848910e-01,  1.16239523e-03, -6.73869327e-02,  8.96331621e-05,
        6.71111122e-02,  2.01299891e-01,  1.76381439e-01,  1.44544961e-02,
       -1.36415318e-01, -3.18108648e-02, -3.51585075e-02,  1.24862537e-01,
        6.54390603e-02, -1.79662079e-01,  8.39038659e-03, -6.52492717e-02,
       -4.79320846e-02, -4.05376814e-02, -1.82695538e-02,  1.35992825e-01,
        6.97307214e-02, -5.41270301e-02,  3.14575769e-02,  2.86752880e-02,
        9.04180668e-03,  3.10734902e-02, -3.88299376e-02, -7.43401796e-02],
      dtype=float32), array([ 0.09236415,  0.05246023, -0.03693461,  0.05469636,  0.05779893,
        0.13331857,  0.21085702, -0.01114039, -0.09325632,  0.07158454,
        0.03167493,  0.13376454,  0.13156445, -0.12092946, -0.02573274,
       -0.05352074,  0.00177706,  0.05248505, -0.07331309,  0.06653137,
       -0.02102634,  0.00347302, -0.19828801, -0.08791062,  0.05434143,
        0.07060813, -0.09335811, -0.04778329, -0.02983012,  0.1595401 ,
        0.01018381, -0.04852933, -0.03336967,  0.02886004,  0.05975606,
        0.0974864 , -0.00946077, -0.06796782], dtype=float32), array([ 7.70701468e-02,  2.34568515e-03, -1.22838043e-01,  6.06604481e-05,
        1.08674861e-01,  2.40898028e-01,  7.23511800e-02, -4.14036550e-02,
       -1.20636895e-01, -2.74732499e-03, -1.84729435e-02,  6.18617162e-02,
        8.97722915e-02, -1.62845016e-01, -1.34318219e-02,  5.31670935e-02,
       -8.27090293e-02, -1.22121066e-01,  1.53016988e-02,  1.22807577e-01,
       -1.36648446e-01,  1.32556446e-02, -8.84201974e-02,  8.29895660e-02,
        5.18502928e-02, -7.32250437e-02,  6.30651340e-02, -9.98577196e-03,
       -4.71815281e-02,  6.02727272e-02, -7.98970908e-02, -2.12689787e-02],
      dtype=float32)], 'names': ['adam', 'adam', 'adam', 'adam', 'adam', 'adam', 'bhalla', 'bhalla', 'bhalla', 'bhalla', 'bhalla', 'bhalla']}

我需要将其保存在 json 文件中。当我调试时，data 显示为 dict 类型，因此我使用 json.dumps(data) 将其保存在 json 文件中，但它抛出以下错误:

TypeError: Object of type 'ndarray' is not JSON serializable

如何解决

Answer 1

添加之前的答案和这个 post ，你可以这样做:

class NumpyEncoder(json.JSONEncoder):
    """ Special json encoder for numpy types """
    def default(self, obj):
        if isinstance(obj, (np.int_, np.intc, np.intp, np.int8,
                            np.int16, np.int32, np.int64, np.uint8,
                            np.uint16, np.uint32, np.uint64)):
            return int(obj)
        elif isinstance(obj, (np.float_, np.float16, np.float32,
                              np.float64)):
            return float(obj)
        elif isinstance(obj, (np.ndarray,)):
            return obj.tolist()
        return json.JSONEncoder.default(self, obj)

然后你就可以打电话了

import numpy as np
import json
operation = json.dumps(data, cls=NumpyEncoder)

如果您正在使用字典并想要保存修改后的字典但收到类似的错误

'TypeError: Object of type intc is not JSON serializable'

你可以使用

dumped = json.dumps(data, cls=NumpyEncoder)
with open('json_file_path.json', 'a') as f:
    f.write(dumped + '\n') 

代码确保保存的 json 文件不包含\splashes，如 here 中所述。