Python if there is only 1 item in list, print an error

Question

I am trying to write some python code, that if there is only 1 term in a list, an error code is printed.

This is my code so far:

#code to put data into seperate lists
inputdata=open("C:\Users\Chloe\Google Drive\Uni\Computing\data.txt", 'r')

for datapoint in inputdata:

    datapoint=datapoint.strip('\n')
    splitdata=datapoint.split(',')
    x.append(splitdata[0])
    y.append(splitdata[1])
    e.append(splitdata[2])

#converting data to float in lists
x=[float(i) for i in x]

y=[float(i) for i in y]

e=[float(i) for i in e]  


print ('the x coordinates for the data points are '+str(x))

print ('the y coordinates for the data points are '+str(y))

print ('the associated error for the data points is '+str(e))

The code works when the correct data is given.

Answer 1

Do you mean:

splitdata=datapoint.split(',')
if len(splitdata) != 3:
    print("Wrong number of things")
else:
    x.append(splitdata[0])
    y.append(splitdata[1])
    e.append(splitdata[2])

or even:

if len(splitdata) != 3:
    raise ValueError("Input data must have three items separated by commas.")