Question

我正在阅读一个大约有7到8行的csv文件，它是我文件的描述。我使用以下代码进入第一列：

            list_of_files = glob.glob('C:/payment_reports/*csv') # * means all if need specific format then *.csv
            latest_file = max(list_of_files, key=os.path.getctime)
            print (latest_file)
            line_count = None
            for row in csv.reader(open(latest_file)):
                if row[0] == 'date/time':
                    print (row)
                    break
            else:
               print("{} not found".format('name'))

由于打印的行是：

，我正在修改行

['date/time', 'settlement id', 'type', 'order id', 'sku', 'description', 'quantity', 'marketplace', 'fulfillment', 'order city', 'order state', 'order postal', 'product sales', 'shipping credits', 'gift wrap credits', 'promotional rebates', 'sales tax collected', 'Marketplace Facilitator Tax', 'selling fees', 'fba fees', 'other transaction fees', 'other', 'total']

现在如何将列+所有行保存为新的csv？我有一个line_count，但在我尝试使用新变量之前，我确信csv中有函数使用行的索引，我可以使用它来使事情变得更简单。你们有什么建议是最好的方法。

解决方案：感谢@bruno desthuilliers

            list_of_files = glob.glob('C:/payment_reports/*csv') # * means all if need specific format then *.csv
            latest_file = max(list_of_files, key=os.path.getctime)
            print (latest_file)
            with open(latest_file, "r") as infile:
                reader = csv.reader(infile)
                for row in reader: 
                    if row[0] == 'date/time':
                        print (row)
                        break
                else:
                    print("{} not found".format('name'))
                    break
                with open("C:/test.csv", "w") as outfile:
                    writer = csv.writer(outfile)
                    writer.writerow(row) # headers
                    writer.writerows(reader) # remaining rows

Answer 1

csv.reader是一个迭代器。每次调用.next时，它都会从csv中读取一行。

以下是文档：http://docs.python.org/2/library/csv.html。

迭代器对象实际上可以从一个太大而无法一次读取的源返回值。使用带有迭代器的for循环有效地在每次循环时调用.next。希望这有帮助吗？

Answer 2

找到标题行后，您可以将其写入剩余的行：

with open(latest_file, "rb") as infile:
    reader = csv.reader(infile)
    for row in reader: 
        if row[0] == 'date/time':
            break
    else:
        print("{} not found".format('name'))
        return
    with open("path/to/new.csv", "wb") as outfile:
        writer = csv.writer(outfile)
        writer.writerow(row) # headers
        writer.writerows(reader) # remaining rows

如何在找到标题行后创建新的csv？

2 个答案: