Write code that uses id() to demonstrate all three of the following, and paste the output into your submission notes:

After b = a, a and b are the same object
After b = a[:], a and b are different objects
But for a nested list, after b = a[:], a[0] and b[0] are still the same object

Part B — going deeper: one class roster, four times over

The six problems in Part A have nothing to do with each other. This part has a single problem — a class roster — but you work it four times: read it in, rank it, survive the dirty version, and then find the scale at which the whole approach falls apart.

The data is thirty lines of text. Each line is student-id name quiz1 quiz2 quiz3:

RAW = [
    "2026001 zhangsan 91 57 59",
    "2026002 lisi 70 81 55",
    "2026003 wangwu 43 65 66",
    "2026004 zhaoliu - 78 90",
    "2026005 qianqi 90 90 61",
    "2026006 sunba 73 91 73",
    "2026007 zhoujiu 60 53 75",
    "2026008 wushi 105 60 70",
    "2026008 wushi 60 70 80",
    "2026009 zhengyi 60 61 69",
    "2026010 chener 57 48 70",
    "2026011 chusan 59 99 46",
    "2026002 lisi 10 10 10",
    "2026012 weisi 43 59 89",
    "2026013 jiangwu 95 96 48",
    "2026014 shenliu 53 73 62",
    "2026015 hanqi 64 73 96",
    "2026016 yangba 59 71 85",
    "2026017 zhujiu 64 41",
    "2026018 qinshi 59 81 93",
    "2026011 chusan 88 88 88",
    "2026019 youyi 97 73 62",
    "   2026020   xuer   70 80 90  ",
    "2026021 hesan 82 90 80",
    "2026022 lvsi 61 55 60",
    "2026023 shiwu 58 x 88",
    "2026024 zhangliu 63 93 95",
    "2026019 youyi 40 40 40",
    "2026025 kongqi 41 100 67",
    "2026026 caoba 99 50 48",
]

Several kinds of mess are hiding in those thirty lines; B-3 deals with them. B-1 and B-2 may assume every line is clean.

No file reading — that is L12. Copy the block above into your own file.

Homework 2

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