在有序字典中添加和更改 key/value 而不改变

Question

我正在尝试使用新键将一个值拆分为三个不同的值，并将它们添加到我的字典中。但我总是收到错误消息：RuntimeError: OrderedDict during iteration

mutated

def csv_to_dic(file):
    with open(file, "r") as csvfile:
        # creat object, that can read csv as dictionary (including key)
        reader = csv.DictReader(csvfile)
        # define students as mutable list of dictionary rows
        students = []
        # read each row in file and save into students (load everything into memory)
        for row in reader:
            students.append(row)
        for i in range(len(students)):
            for k, v in students[i].items():
                if k == 'name':
                    string = v.split()
                    students[i].update({'first' : string[0]})
                    students[i].update({'middle' : string[1]})
                    students[i].update({'last' : string[2]})
        return students

我可以看到，我可以像这样更改键的值：

            if k == 'name':
                string = v.split()
                students[i][k] = string[0]

但我无法更改密钥或添加新密钥。我做错了什么？

Answer 1

固定：

    for row in reader:
        students.append(row)
    for i in range(len(students)):
        name = students[i].get('name')
        name = name.split()
        if len(name) == 3:
            students[i]['first'] = name[0]
            students[i]['middle'] = name[1]
            students[i]['last'] = name[2]
            students[i].pop('name')
        else:
            students[i]['first'] = name[0]
            students[i]['middle'] = None
            students[i]['last'] = name[1]
            students[i].pop('name')
    return students

这部分似乎是多余的并且会导致问题，但我不确定为什么：

        for k, v in students[i].items():
            if k == 'name':

在有序字典中添加和更改 key/value 而不改变

Add and change key/value in ordered dictionary without mutating

key

add

mutated

ordereddict