import csv

firsrCol = []
with open('C:\\Users\\Administrator\\Desktop\\owid-covid-data.csv', 'r') as f:
    reader = csv.reader(f)
    result = list(reader)
    for key in result:
        # print(key)
        firsrCol.append(key[1])
    newData = [i for n, i in enumerate(firsrCol) if i not in firsrCol[:n]]  # 数组去重

    record = []
    maxTime = ''
    for ll in newData:
        arr = []
        for key in result:
            if key[1] == ll:
                bbbb = key[2].replace("-", "")
                # print(bbbb)
                arr.append(bbbb)
        maxTime = max(arr)
        obj = {
            "name": ll,
            "time": maxTime
        }
        print(obj)
        record.append(obj)
    print(record)
    finallData = []
    for rec in record:
        for key in result:
            time = rec["time"][:4] + '-' + str(rec["time"][4:6]) + '-' + str(rec["time"][6:8])
            if rec["name"] == key[1] and time == key[2]:
                finallData.append(key)

    csvFile = open("C:\\Users\\Administrator\\Desktop\\owid-covid-data(1).csv", "w")  # 创建csv文件
    writer = csv.writer(csvFile)  # 创建写的对象
    # 先写入columns_name
    writer.writerow(["continent", "location", "date", "new_cases_per_million"])  # 写入列的名称
    # 写入多行用writerows                                #写入多行
    writer.writerows(finallData)   # writer.writerows([[1,a,b],[2,c,d],[3,d,e]])

    print(finallData)
    print(len(newData))