Hi
Basicaly, heres some example that you can try

record = self.env['model.model'].search([('id','=',1)])
updated_data = {
    'o2m_field':[
    (0,0,{
        'name':'line no #1',
        'otherfield':'*****'
        })
    ,(0,0,{
        'name':'line no #2',
        'otherfield':'*****'
        })
    ,(0,0,{
        'name':'line no #3',
        'otherfield':'*****'
        })
    ]
}
record.write(updated_data)


In your case,, you have list key = [a, b, c, d, e, f]
So you must map the values before write it

o2mfield_value = [
    (0,0,{
        'name':'a',
        })
    ,(0,0,{
        'name':'b',
        })
    ,(0,0,{
        'name':'c',
        })
    # ,********* UNTIL "f"
]


Hope Helps

Regards
La Jayuhni Yarsyah