>>> x = "qwertyui"
>>> chunks, chunk_size = len(x), len(x)//4
>>> [ x[i:i+chunk_size] for i in range(0, chunks, chunk_size) ]
['qw', 'er', 'ty', 'ui']

This is called slicing:

>>> paragraph[:5], paragraph[5:]
('my pa', 'ragraph')

To answer the "split every X characters" question, you would need a loop:

>>> x = 5
>>> [paragraph[i: i + x] for i in range(0, len(paragraph), x)]
['my pa', 'ragra', 'ph']

There are more solutions to this though, see:

• Split python string every nth character?
• What is the most "pythonic" way to iterate over a list in chunks?

One solution would be to use this function:

def chunkstring(string, length):
    return (string[0+i:length+i] for i in range(0, len(string), length))

This function returns a generator, using a generator comprehension. The generator returns the string sliced, from 0 + a multiple of the length of the chunks, to the length of the chunks + a multiple of the length of the chunks.

You can iterate over the generator like a list, tuple or string - for i in chunkstring(s,n): , or convert it into a list (for instance) with list(generator). Generators are more memory efficient than lists because they generator their elements as they are needed, not all at once, however they lack certain features like indexing.

This generator also contains any smaller chunk at the end:

>>> list(chunkstring("abcdefghijklmnopqrstuvwxyz", 5))
['abcde', 'fghij', 'klmno', 'pqrst', 'uvwxy', 'z']

Example usage:

text = """This is the first line.
           This is the second line.
           The line below is true.
           The line above is false.
           A short line.
           A very very very very very very very very very long line.
           A self-referential line.
           The last line.
        """

lines = (i.strip() for i in text.splitlines())

for line in lines:
    for chunk in chunkstring(line, 16):
        print(chunk)

Here's a function that will break a string into c equal size chunks, with the last chunk containing any overflow:

def split_str(strng, c):
    l = len(strng) // c
    r = [strng[n * l:(n + 1) * l] for n in range(c - 1)]
    r.append(strng[(c - 1) * l:])
    return r

s = 'Now is the time for all good men to come to the aid'

print(split_str(s, 4))

Result:

['Now is the t', 'ime for all ', 'good men to ', 'come to the aid']

You can simplify the function a bit if you know that the string will always divide evenly. Then it would be just:

def split_str(str, c):
    l = len(str) // c
    r = [str[n*l:(n+1)*l] for n in range(c)]

The rest is just math, which it sounds like you already have a handle on. Or do you need help finding the factors of a number? I know there are lots of questions about that already on SO.

split_string_list = [string[x:x+4] for x in range(0,len(string),4)]

Try that

Basically what it is a list generated such that it starts with elements 0-4, then 4-8, etc. which is exactly what you want, typecasted into a string