How do I delete empty lists in my list of lists?

This line here has a problem:

   results = [[int(entry) for entry in line.split() != []] for line in f.readlines()] 
#                                                  ^-- falta um IF

When you use for conditionally, you should use the

for name in list if condition

That in your case, should be something like:

   results = [[int(entry) for entry in line.split() if entry != []] for line ... etc

So when entry is empty, it will not be added to the inner list of results

Enjoying, you can by a condition in the list outside, to filter empty lines if you want:

   results = [...  igual linha de cima ...] for line in f.readlines() if line.split()] 

Here, line.split() will be considered true if it is not blank.

If you're having a hard time understanding the peculiarities of Py, here is a less cryptic alternative to the code, which can be easily adapted to lists:

  

How to read hyphen-separated numbers in a text file?

Bacco's answer explains well what the problem was, but I would like to add some comments.

The readlines function will read the entire contents of the file at once, placing each line of the file in an item in a list. For small files - and for memory-wasting applications - this will not be a problem, but if you need to process very large files, it will be a problem. One way around this is by using generators. It is possible to work with each line of the file separately, reading one by one and doing the necessary processing. To define a generator, simply use yield :

def list_of_integers(filename):
    with open(filename) as stream:
        for line in stream:
            line = line.strip()
            if line:
                yield [int(number) for number in line.split()]

So you can scroll through all the lines as follows:

for numbers in list_of_integers('C:/Anaconda/loto.txt'):
    print(numbers)

The result would be:

[1, 2, 3, 4, 5, 6, 7, 8, 9]
[2, 3, 4, 5, 6, 7, 6, 8, 9]
[3, 4, 5, 6, 7, 7, 8, 8, 9]
[1, 2, 3, 4, 5, 6, 7, 8, 9]
[4, 5, 6, 7, 8, 9, 10, 11]
[5, 6, 7, 6, 7, 8, 8, 9, 15]

See working at Repl.it

Other comments:

• When opening the read-only file, you can omit the mode argument, 'r' ;
• Avoid variables named f because they will not be readable during the code;
• If the rows in the file are too large, you may want to return a generator generator by replacing the brackets in yield with parentheses. In this way, the line will stay in memory only once and not twice - even if for a short time;
• The strip function is required because, in this case, the \n character is held in line ;