将文件元素读取到3个不同的数组中

Question

I have a file that is space delimited with values for x,y,x. I need to visualise the data so I guess I need so read the file into 3 separate arrays (X,Y,Z) and then plot them. How do I read the file into 3 seperate arrays I have this so far which removes the white space element at the end of every line.

def fread(f=None):
    """Reads in test and training CSVs."""
    X = []
    Y = []
    Z = []

    if (f==None):
        print("No file given to read, exiting...")
        sys.exit(1)

    read = csv.reader(open(f,'r'),delimiter = ' ')
    for line in read:
        line = line[:-1]

I tried to add something like:

for x,y,z in line:
    X.append(x)
    Y.append(y)
    Z.append(z)

But I get an error like "ValueError: too many values to unpack"

I have done lots of googling but nothing seems to address having to read in a file into a separate array every element.

I should add my data isn't sorted nicely into rows/columns it just looks like this "107745590026 2 0.02934046648 0.01023879368 3.331810236 2 0.02727724425 0.07867902517 3.319272757 2 0.01784882881"......

Thanks!

Answer 1

EDIT : If your data isn't actually separated into 3-element lines (and is instead one long space-separated list of values), you could use python list slicing with stride to make this easier:

X = read[::3]
Y = read[1::3]
Z = read[2::3]

---

This error might be happening because some of the lines in read contain more than three space-separated values. It's unclear from your question exactly what you'd want to do in these cases. If you're using python 3, you could put the first element of a line into X , the second into Y , and all the rest of that line into Z with the following:

for x, y, *z in line:
    X.append(x)
    Y.append(y)
    for elem in z:
        Z.append(elem)

If you're not using python 3, you can perform the same basic logic in a slightly more verbose way:

for i, elem in line:
    if i == 0:
        X.append(elem)
    elif i == 1:
        Y.append(elem)
    else:
        Z.append(elem)