Question

In DrRacket, is there any way I can change (list 1 (list 2 (list 3 4 5) 6 )7) to (list 1 2 3 4 5 6 7)?

Answer 1

Solution to given question:

Yes, there are multiple ways to convert any nested list to normal form

Three possible ways mnetioned here:

=======================================

1) Code

import collections

from itertools import chain

#input list called L

L = [1,2,[3,4,5],6,7]

#if an item in the list is not already a list, then put it in one.

a = [i if isinstance(i, collections.Iterable) else [i,] for i in L]

#flattens out a list of iterators

b = list(chain.from_iterable(a))

print b

#[1, 2, 3, 4, 5, 6, 7]

===============================================================

2)

L = [1,2,[3,4,5],6,7]

new_list = []

[new_list.extend(x) if type(x) is list else new_list.append(x) for x in L]

print new_list

(or)

3)

new_list2 = []

for item in L:

    if type(item) is list:

        new_list2.extend(item)

    else:

        new_list2.append(item)

print new_list2