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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def _lenstr(ins):
    ''' Returns string length
    '''
    (tmp1, output) = _str_oper(ins.quad[2], no_exaf=True)
    if tmp1:
        output.append('push hl')

    output.append('call __STRLEN')
    output.extend(_free_sequence(tmp1))
    output.append('push hl')
    REQUIRES.add('strlen.asm')
    return output