Python-сообщество

 def hide_symbol(string):
    # 8, 11-15
    string_list = []
    for elem in string:
        if elem == string[6] or elem == string[11]:
            hidden_elem = '*'
            string_list.append(hidden_elem)
        else:
            string_list.append(elem)
    hidden_string = ''.join(string_list)
    return hidden_string
abc = 'DS3G54R3G5HDF3G1D31'
hidden_string = hide_symbol(abc)
print(hidden_string)

 def hide_symbol(string):
    # 8, 11-15
    string_list = list(string)
    for i,_ in enumerate(string_list):
        if i+1 in (8, 11,15):
            string_list[i] = '*'
    return ''.join(string_list)
abc = 'DS3G54R3G5HDF3G1D31'
hidden_string = hide_symbol(abc)
print(hidden_string)

 if elem == string[6] or elem == string[11]:

 def hide_symbol(string):
    s = list(string)
    s[6] = '*'
    s[11] = '*'
    return ''.join(s)

 def hide_symbol(strg, trgr, smbl):
    for i in trgr:
        out = ''
        count = 0
        for j in strg:
            if count == i - 1:
                out += smbl
                count = 0
            else:
                out += j
                count += 1
        strg = out
    return out
abc = 'DS3G54R3G5HDF3G1D31'
trgr = (6, 11)
smbl = '*'
print(hide_symbol(abc, trgr, smbl))

 DS3G5*R3G5**F3G1D*1