並行登錄到兩個CSV文件（python）

Question

我正在讀取一系列氣候數據文本文件，每個文件包含9000行，第一行是氣象站的信息，例如名稱，經度等。 從8到末端的線包含氣候數據。

我想讀取所有文件並輸出兩個文件“ MetLocations.csv”和“ MetData.csv”，其中第一個文件包含所有文件的第一行的集合，而第二個文件包含所有氣候數據。

我遍歷了所有文件，閱讀了信息，並毫無疑問地打印了它們，除了一個奇怪的問題。 當我進行兩次“ with”循環時，文件MetLocations.csv留為空白，而當我逐次進行循環處理時，它寫得很好！ 請查看代碼以獲得更清晰的視圖。

這是我的代碼的一部分：

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)

在運行上述代碼的最后，我發現文件MetData.csv充滿了數據，而文件MetLocations.csv為空！

奇怪的是，當我運行相同的代碼並注釋了最后4行底行時，MetLocations.csv會充滿問題！

是否不允許打開兩個連續的CSV文件進行追加？ 或我的代碼中錯誤的部分是什么？

非常感謝您的幫助。

Answer 1

您需要在同一行中打開所有文件，以便成為同一上下文的一部分：

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