x = 'An apple a day, keeps the doctor away'
i, j = x.find('a', 0), []
while i != -1:
j.append(i)
i = x.find('a', i+1)
print(j)
eCA9ICdBbiBhcHBsZSBhIGRheSwga2VlcHMgdGhlIGRvY3RvciBhd2F5JwoKaSwgaiA9IHguZmluZCgnYScsIDApLCBbXQp3aGlsZSAgaSAhPSAtMToKCWouYXBwZW5kKGkpCglpID0geC5maW5kKCdhJywgaSsxKQoJcHJpbnQoaik=
[3]
[3, 9]
[3, 9, 12]
[3, 9, 12, 33]
[3, 9, 12, 33, 35]