<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _replace_tabs(s, ts=8):
 """ Replace the tabs in 's' and keep its original alignment with the tab-stop equals to 'ts' """

    result = ''
    for c in s:
        if c == '\t':
            while True:
                result += ' '
                if len(result) % ts == 0:
                    break
        else:
            result += c
    return result