```
def bubblesort(seq)：
  for i in range(len(seq))：
    for j in range(len(seq)-1)：
      if int(seq[j])>int(seq[1+j])：
        seq[j], seq[1+j] = seq[1+j], seq[j]
  return seq
```
def bubblesort(seq):
  for i in range(len(seq)):
    for j in range(len(seq)-1):
      if int(seq[j])>int(seq[1+j]):
        seq[j], seq[1+j] = seq[1+j], seq[j]
  return seq