How to create a list from another list in python

Question

I am very new to python and i was stuck with this. I need to create a list of lists that is formed from this list c: ['asdf','bbnm','rtyu','qwer'].

I need to create something like this:

b: [['a','s','d','f'],['b','b','n','m'],['r','t','y','u'],['q','w','e','r']]

I tried using a for-loop, but it is not working out. I don't know what mistake I am making.

• millimoose: Show us what you mean with "I tried", and what you mean "it is not working out". It's hard to tell what your mistake is otherwise.
• millimoose: That said, [list(s) for s in c] should work. list(x) converts any sequence into a list of its elements, and a str is a sequence of its characters. The surrounding stuff is a list comprehension.
• Erik Kaplun: Why do you need this? You can iterate over a string just as well as a list—what is it that strictly requires a list?

Answer 1

You can use a list comprehension with list():

>>> c = ['asdf','bbnm','rtyu','qwer']
>>> 
>>> b = [list(s) for s in c]
>>> b
[['a', 's', 'd', 'f'], ['b', 'b', 'n', 'm'], ['r', 't', 'y', 'u'], ['q', 'w', 'e', 'r']]

Notice that calling list() with a string argument returns a list containing the characters of that string:

>>> list('abc')
['a', 'b', 'c']

What we're doing above is applying this to every element of the list via the comprehension.

Answer 2

Use map function.

>>> a= ['asdf','bbnm','rtyu','qwer']
>>> map(list ,a )
[['a', 's', 'd', 'f'], ['b', 'b', 'n', 'm'], ['r', 't', 'y', 'u'], ['q', 'w', 'e', 'r']]
>>> 

Answer 3

You could do something that's easier to understand:

b = []
for x in c:
 list(x).append(b)