How to join every sublist to a single string in Python?

Question

Here is the list :

L=[['1', '1', '0', '0', '0'],['1', '1', '1', '1', '0'],['0', '0', '1', '1', '0']]

My desired list would be :

 D=['11000','11110','00110']

There are two steps to the problem, and each is a common duplicate. `''.join` can join a list of strings; apply that to each list in the list of lists. — Karl Knechtel, Sep 06 '22 at 04:49

score 5 · Answer 1 · edited Sep 08 '18 at 22:50

5

L = [['1', '1', '0', '0', '0'],['1', '1', '1', '1', '0'],['0', '0', '1', '1', '0']]
D = [''.join(sub_list) for sub_list in L]

edited Sep 08 '18 at 22:50

user3483203

answered Jan 29 '17 at 20:20

abigperson

score 2 · Answer 2 · answered Jan 29 '17 at 20:36

You can either use a list comprehension:

L = [
    ['1', '1', '0', '0', '0'],
    ['1', '1', '1', '1', '0'],
    ['0', '0', '1', '1', '0']
    ]

D = [''.join(l) for l in L]

or the map function:

D = map(''.join, L) # returns a generator in python3, cast it to list to get one

Note that the most pythonic way of doing this is the list comprehension.

score 0 · Answer 3 · answered Jul 01 '19 at 22:06

flat list can be made through `reduce` easily.

All you need to use initializer - third argument in the reduce function.

reduce(
   lambda result, _list: result.append(''.join(_list)) or result, 
   L, 
   [])

import operator
map(lambda l: reduce(operator.iconcat, l), L)

Above code works for both python2 and python3, but you need to import reduce module as from functools import reduce. Refer below link for details.