python - 将带有数组的列表从 csv 文件转换为 float

Question

我有一个 csv 文件，其中包含加速度计和陀螺仪数据的各种参数的样本列表。它包含 float (IQR、Range、MAD、...)和数组(ZCD 值)。当我读回它时，它们以字符串形式返回，对于我的处理，我需要数字(int/float)。我试过了

    results = map(int, results)

和

results = [int(i) for i in results]

我从 here 得到它们，但我遇到了数组问题。

Traceback (most recent call last):
 File "/home/pi/Desktop/imu/mpu_v16.py", line 458, in <module>
  main()
 File "/home/pi/Desktop/imu/mpu_v16.py", line 439, in main
  compare()
 File "/home/pi/Desktop/imu/mpu_v16.py", line 305, in compare
  nrow = [float(i) for i in nrow]
ValueError: could not convert string to float: [ 53  73  79 139]

我该如何解决这个问题？

我正在添加我的数据样本:

    C,3.3440452548950501e-17,0.99999999999999645,0.89244290726827058,1.7947499048650259,3.3651560716219242,[108 123 149 220 235],0.99999999999999822,110223.99999999971,331.99999999999915,-5.9524005537131887e-17,0.99999999999999989,0.81051947660768831,1.4756039753111405,4.4268119259334213,[103 122 160 205 212],0.99999999999999989,110224.00000000001,332.00000000000006,-6.4540073419474463e-17,0.999999999999999,0.74198651253618131,0.63512619216067612,4.256170326687128,[106 164 192 226],0.99999999999999933,110224.00000000001,332.00000000000006,2.083131190971185e-16,1.0000000000000009,0.66659374901400581,0.52759419283475883,4.5104130995285256,[  7  14  45  56 150 327],1.0000000000000002,110223.99999999994,331.99999999999983,-3.0890618042093025e-17,0.99999999999999667,0.58289607514346964,0.21669963911591134,4.7919240951669444,[ 82 149 208],0.99999999999999822,110223.99999999942,331.99999999999824,-3.2771643497971487e-16,1.0000000000000009,0.58746356061392535,0.29681486739557372,5.2741718744905794,[ 26  48  59  66 114 171 231 242],1.0000000000000002,110224.00000000036,332.00000000000108,-0.57536274345915739,0.147595080030029,0.13018399571123057

Answer 1

您的 csv 格式不正确，或者您读取的内容不正确。您提取的不是单个数字，而是方括号中的多个数字。查看错误信息:

ValueError: could not convert string to float: [ 53  73  79 139]
            ###              This is your data ^               ^

所以当你实际上应该有 [["53", "73 ", "79", "139"], ["123", "12", "11"]] 或 ["53", "73", "79", "139", “123”、“12”、“11”]。

如果您的 csv 格式不正确，您可以通过拆分错误值来即时更正此问题。这将为您提供一个平面列表，如 [53, 73, 79, 139]:

nrow = [float(i) for elem in nrow for i in elem.strip('[] ').split()]
#                ^              ^ extract every sequence of numbers
#                                          ^              ^ remove [] and whitespace around sequences
#                                                            ^     ^ split the actual numbers

这将为您提供一个列表列表，例如 [[ 53, 73, 79, 139], ...]:

    nrow = [[float(i) for i in elem.strip('[] ').split()] for elem in nrow ]