how to create a list of lists

Question

My Python code generates a list everytime it loops:

list = np.genfromtxt(\'temp.txt\', usecols=3, dtype=[(\'floatname\',\'float\')], skip_header=1)
         


        

Answer 1

You want to create an empty list, then append the created list to it. This will give you the list of lists. Example:

>>> l = []
>>> l.append([1,2,3])
>>> l.append([4,5,6])
>>> l
[[1, 2, 3], [4, 5, 6]]