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Question

所以我收集数据并将这些数据保存到csv文件中，但是出于演示目的，我想根据它的相关“顺序”重新排序每个csv文件中的列。

我使用这个问题（write CSV columns out in a different order in Python）作为指导，但我不确定为什么我会收到错误

writeindices = [name2index[name] for name in writenames]
KeyError: % Processor Time

我跑的时候。请注意，此错误似乎不仅限于字符串% Processor Time'。

我哪里错了？

这是我的代码：

CPU_order=["%"+" Processor Time", "%"+" User Time", "Other"]
Memory_order=["Available Bytes", "Pages/sec", "Pages Output/sec", "Pages Input/sec", "Page Faults/sec"]

def reorder_csv(path,title,input_file):
    if title == 'CPU':
        order=CPU_order
    elif title == 'Memory':
        order=Memory_order

    output_file=path+'/'+title+'_reorder'+'.csv'

    writenames = order

    reader = csv.reader(input_file)
    writer = csv.writer(open(output_file, 'wb'))

    readnames = reader.next()
    name2index = dict((name, index) for index, name in enumerate(readnames))
    writeindices = [name2index[name] for name in writenames]
    reorderfunc = operator.itemgetter(*writeindices)
    writer.writerow(writenames)

    for row in reader:
        writer.writerow(reorderfunc(row))

以下是输入CSV文件的示例：

,CPU\% User Time,CPU\% Processor Time,CPU\Other
05/23/2016 06:01:51.552,0,0,0
05/23/2016 06:02:01.567,0.038940741537158409,0.62259056657940626,0.077882481554869071
05/23/2016 06:02:11.566,0.03900149141703179,0.77956981074955856,0
05/23/2016 06:02:21.566,0,0,0
05/23/2016 06:02:31.566,0,1.1695867249963632,0

Answer 1

您的代码有效。您的数据没有名为“％Processor Time ”的列。以下是我使用的示例数据：

Other,% User Time,% Processor Time
o1,u1,p1
o2,u2,p2

以下是我所说的代码：

reorder_csv('.', 'CPU', open('data.csv'))

使用这些设置，一切正常。请检查您的数据。

更新

现在我看到了您的数据，看起来您的列名称如“CPU \％Processor Time ”并希望将其转换为“％Processor Time “在写出之前。您需要做的就是以这种方式创建name2index：

name2index = dict((name.replace('CPU\\', ''), index) for index, name in enumerate(readnames))

这里的区别在于name而不是name.replace('CPU\\', '')，你应该csv.DictReader，它摆脱了 CPU \ 部分。

更新2

我将您的代码重新设计为使用csv.DictWriter和transformer。我还假设“ CPU \％Prvileged Time ”将转换为“其他”。如果不是这种情况，您可以在import csv import os def rename_columns(row): """ Take a row (dictionary) of data and return a new row with columns renamed """ transformer = { 'CPU\\% User Time': '% User Time', 'CPU\\% Processor Time': '% Processor Time', 'CPU\\% Privileged Time': 'Other', } new_row = {transformer.get(k, k): v for k, v in row.items()} return new_row def reorder_csv(path, title, input_file): header = dict( CPU=["% Processor Time", "% User Time", "Other"], Memory=["Available Bytes", "Pages/sec", "Pages Output/sec", "Pages Input/sec", "Page Faults/sec"], ) reader = csv.DictReader(input_file) output_filename = os.path.join(path, '{}_reorder2.csv'.format(title)) with open(output_filename, 'wb') as outfile: # Create a new writer where each row is a dictionary. # If the row contains extra keys, ignore them writer = csv.DictWriter(outfile, header[title], extrasaction='ignore') writer.writeheader() for row in reader: # Each row is a dictionary, not list print row row = rename_columns(row) print row print writer.writerow(row)词典中修复它。

StudentRec.birthdate = fields[i];
string[] format = { "MM/dd/yy" };
DateTime dateValue;
if (StudentRec.birthdate.Length > 0)
{
    if (!DateTime.TryParseExact(StudentRec.birthdate, format,
                                new CultureInfo("en-US"),
                                DateTimeStyles.AllowWhiteSpaces , 
                                out dateValue))
    {  
        Console.WriteLine(StudentRec.birthdate);
        throw new MyException("Birthdate is not valid   ", o, strCNFileErr);
    }
}

Python：重新排序csv文件的列

1 个答案:

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