并行记录到两个 CSV 文件（python）

Question

我正在阅读一系列气候数据文本文件，每个文件包含 9000 行，第一行是站名、经度等信息。 从 8 到末尾的行包含气候数据。

我想读取所有文件并输出两个文件“MetLocations.csv”和“MetData.csv”，其中第一个文件由所有文件的第一行的集合组成，而第二个文件由所有文件组成气候数据。

我遍历了所有文件，阅读了信息，然后打印出来，除了一个奇怪的问题之外没有任何问题。当我做一个双'with'循环时，文件 MetLocations.csv 是空的，而当我一个接一个地循环时，它写得很好！ 请查看代码以获得更清晰的视图。

这是我的代码的一部分：

with open('MetLocations.csv','wb+') as locations:
    wr_loc = csv.writer(locations, quoting=csv.QUOTE_NONE, quotechar='', delimiter=',', escapechar='\\')
    headers = ["St_Id","City","State","Country","Source","WO code","Lat","Long","TimeZone","Alt"]
    wr_loc.writerow(headers)
    with open('MetData.csv','a+')as met_data:
        wr_data = csv.writer(met_data, quoting=csv.QUOTE_NONE, quotechar='', delimiter=',', escapechar='\\',lineterminator='\n')
        headers = ["St_ID", "Year", "Month", "Day", "Hour", "Minute", "Data Source and Uncertainty Flags", "Dry Bulb Temperature"]
        wr_data.writerow(headers)

            for n, f in enumerate(filenames):
                print n, f,time.strftime('%Y-%m-%d %H:%M:%S')
                full_path = os.path.join(source, f)
                with open(full_path, 'r') as input_file:
                    content = input_file.readlines()
                    location = [n] + list_elements(content[0])[1:]
                    wr_loc.writerow(location)
                    meteo = []
                    for line in content[8:]:
                        meteo.append([n] + list_elements(line))
                    wr_data.writerows(meteo)

在上面的代码运行结束时，我发现文件 MetData.csv 中充满了数据，而文件 MetLocations.csv 是空的！

奇怪的是，当我在最后 4 行注释的情况下运行相同的代码时，MetLocations.csv 被毫无问题地填充！

是否不允许打开两个连续的 CSV 文件进行追加？ 或者我的代码有什么错误？

非常感谢您的帮助。

Answer 1

您需要在同一行中打开所有文件，以便它们属于同一上下文：

with open('MetLocations.csv','wb+') as locations, open('MetData.csv','w')as met_data:

     wr_loc = csv.writer(locations,
                         quoting=csv.QUOTE_NONE,
                         quotechar='', delimiter=',', escapechar='\\')

     wr_data = csv.writer(met_data,
                          quoting=csv.QUOTE_NONE,
                          quotechar='', delimiter=',',
                          escapechar='\\',lineterminator='\n')

     headers = ["St_Id","City","State","Country","Source","WO code","Lat","Long","TimeZone","Alt"]
     wr_loc.writerow(headers)

     headers = ["St_ID", "Year", "Month", "Day", "Hour", "Minute", "Data Source and Uncertainty Flags", "Dry Bulb Temperature"]
     wr_data.writerow(headers)

     for n, f in enumerate(filenames):
         print n, f,time.strftime('%Y-%m-%d %H:%M:%S')
         full_path = os.path.join(source, f)
         with open(full_path, 'r') as input_file:
            # your code here