1l = list('abcd') # ['a', 'b', 'c', 'd']
2l = map(None, 'abcd') # ['a', 'b', 'c', 'd']
3l = [i for i in 'abcd'] # ['a', 'b', 'c', 'd']
4
5import re # importing regular expression module
6l = re.findall('.', 'abcd')
7print(l) # ['a', 'b', 'c', 'd']