import csv
cols = [' V1', ' I1'] # define your columns here, check the spaces!
data = [[] for col in cols] # this creates a list of **different** lists, not a list of pointers to the same list like you did in [[]]*len(positions)
with open('data.csv', 'r') as f:
for rec in csv.DictReader(f):
for l, col in zip(data, cols):
l.append(float(rec[col]))
print data
# [[3.0, 3.0], [0.01, 0.01]]