python - 如何将嵌套字典中的键输出到csv

Question

我正在尝试将嵌套字典写入 CSV。我已经能够成功地做到这一点，但是因为字典没有排序，所以我无法分辨哪一列是哪一列。如何将键输出为列标题，以便我可以区分哪一列？

import datetime
import csv

d = {
        u'Project 1': {'Start Date': datetime.datetime(2015, 5, 6, 0, 0), 'Finish Date': datetime.datetime(2015, 12, 23, 0, 0)},
        u'Project 2': {'Start Date': datetime.datetime(2015, 1, 23, 0, 0), 'Finish Date': datetime.datetime(2015, 12, 22, 0, 0)}
}

milestones = d.values()[0].keys()
for key, value in d.items():
    print [key] + [d[key][date] for date in milestones]

writer = csv.writer(open('C:\\test.csv', 'wb'))
for key, value in d.items():
    writer.writerow([key] + [d[key][date] for date in milestones])

Answer 1

使用csv.DictWriter (这是一个示例，请根据您的需要进行修改):

import csv

with open('test.csv', 'w') as csvfile:
    # put all keys you want to write here
    fieldnames = ['Project Name', 'Start Date', 'Finish Date']
    writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
    writer.writeheader()

    for project_name, project_dict in d.iteritems():
        # add project name
        row_dict = dict(
            [("Project Name", project_name)] + project_dict.items()
        )
        # write row
        writer.writerow(row_dict)