How to plot multiple points from a list using matplotlib?

It's clear ! when you do your split there is 4 values

content = ['2.449,14.651,-0.992,', '6.833,13.875,-1.021,', '8.133,17.431,-1.150,', '3.039,13.724,-0.999,', '16.835,9.456,-1.031,', '16.835,9.457,-1.031,', '15.388,5.893,-0.868,', '13.743,25.743,-1.394,', '14.691,24.988,-1.387,', '15.801,25.161,-1.463,', '14.668,23.056,-1.382,', '22.378,20.268,-1.457,', '21.121,17.041,-1.353,', '19.472,13.555,-1.192,', '22.498,20.115,-1.436,', '13.344,-33.672,-0.282,', '13.329,-33.835,-0.279,', '13.147,-30.690,-0.305,', '13.097,-28.407,-0.339,', '13.251,-28.643,-0.366,', '13.527,-25.067,-0.481,', '19.433,-33.137,-0.408,', '19.445,-29.501,-0.345,', '20.592,-28.004,-0.312,', '19.109,-26.512,-0.380,', '18.521,-24.155,-0.519,', '22.837,48.245,-2.201,', '23.269,50.129,-2.282,', '23.499,46.652,-2.297,', '23.814,48.646,-2.271,', '30.377,46.501,-2.214,', '29.869,44.479,-2.143,', '29.597,41.257,-2.018,', '28.134,40.291,-2.159,', '-40.932,-0.320,-1.390,', '-36.808,0.442,-1.382,', '-30.831,0.548,-1.288,', '-29.404,1.235,-1.300,', '-26.453,1.424,-1.261,', '-30.559,2.775,-1.249,', '-27.714,3.439,-1.201,']

Solution:

for value in content:
    x, y, z,parasitic_value = value.split(',')

The element in content are:

'2.449,14.651,-0.992,'

A slightly different way to extract the data to plot from this string is to consider it as a tuple, and to use eval().

data = [eval("("+x[:len(x)-1]+")") for x in content]

Which returns:

[(2.449, 14.651, -0.992),
 (6.833, 13.875, -1.021),
 (8.133, 17.431, -1.15),
 ...
 (-30.559, 2.775, -1.249),
 (-27.714, 3.439, -1.201)]

EDIT: the error you got means:

You want 3 values, X, Y and Z; but when I split at ",", There are more (too many values to unpack).

content[0].split(",")
Out[4]: ['2.449', '14.651', '-0.992', '']

I see at least one error in there.

The most obvious one (because you got an error), is in splitting. The third comma at the end is causing the string to be split into four elements

>>> l = 'a,b,c,'
>>> l.split(',')
['a', 'b', 'c', '']

you can work around that by using:

x,y,z,_ = value.split(',')

the next problem you'll run into is with your loop

for value in content:
    x, y, z = value.split(',')

you are only storing the last of your values, since you overwrite them multiple times. The easiest way to work around this is creating three lists and appending into them:

x = []
y = []
z = []
for measurement in content:
    a,b,c,_ = measurement.split(',')
    x.append(a)
    y.append(b)
    z.append(c)

This is not the most efficient way, but I think it should be easier to understand.

I recommend using it like this:

x = []
y = []
z = []
with open('measurements.txt') as file:
    for line in file:
        a,b,c,_ = line.split(',')
        x.append(a)
        y.append(b)
        z.append(c)

To solve the main issue , you have to edit the list , and make it a 3d numpy array , by copying all the values , traversing the list via re.

Rather than assuming the list as multiple points , try to take the first 2 points or 3 points as a image/3D graph , and use imshow or Axes3D to plot it.