通过重新排列列和行来重写 csv 文件

Question

我有一个csv文件(我们称之为input.csv(，看起来像这样：

ID; Text_1; Points_1; Text_2; Points_2
1; "Hello world one"; 33; "Hello world two"; 90
2, "Goodbye world one"; 44; "Goodbye world two";100

我想创建另一个 csv 文件(我们称之为 output.csv(，它像这样重新排列列：

 ID; Field; Sent; Points;
 1; Text_1;"Hello world one"; 33
 1; Text_2;"Hello world two"; 90
 2; Text_1;"Goodbye world one"; 44
 2; Text_2;"Goodbye world two"; 100

这似乎并不像我想象的那么容易。我想知道是否有办法直接转录文件。提前谢谢。

我已经在一些帮助下尝试过这个，但我很难按照我所说的顺序阅读和复制列和行。

with open("results.csv", "r") as text:
    reader = csv.DictReader(text, delimiter=";")
rows = [l.split(";") for l in text.split("n")]
del filas[0] 
newlist = list()
for l in filas:
  newlist.append([l[0], 'Texto_1', l[2]])
  newlist.append([l[0], 'Texto_2', l[4]])

Answer 1

只需读取每一行并使用适当的字段写出两行：

import csv
with open('input.csv','r',newline='') as infile:
    with open('output.csv','w',newline='') as outfile:
        r = csv.reader(infile,delimiter=';')
        w = csv.writer(outfile,delimiter=';')
        next(r) # skip the original header
        w.writerow('ID Field Sent Points'.split())
        for id,t1,p1,t2,p2 in r:
            w.writerows([[id,'Text_1',t1,p1],
                         [id,'Text_2',t2,p2]])

输出：

ID;Field;Sent;Points
1;Text_1;Hello world one;33
1;Text_2;Hello world two;90
2;Text_1;Goodbye world one;44
2;Text_2;Goodbye world two;100

注： 除非字段包含分隔符，否则.csv模块不需要引号。 如果需要，还有其他选项可以csv.writer报价。

Answer 2

你可以试试这个：

def get_data()
   with open('filename.csv') as f:
      data = [i.strip('n').split('; ') for i in f]
      header = data[0]
      for i, a in enumerate(data):
          yield [data[0], header[1], data[1], data[2]]
          yield [data[0], header[3], data[3], data[4]]
final_data = ['; '.join(i) for i in get_data()]

Answer 3

下面的代码不会为您提供确切的查找内容，但我相信它将帮助您重新组织csv文件中的列。

import csv
with open('input.csv', 'r') as infile, open('output.csv', 'w') as outfile:
    # output dict needs a list for new column ordering
    fieldnames = ['ID', 'Text_1', 'Text_2', 'Points_1', 'Points_2']
    writer = csv.DictWriter(outfile, fieldnames=fieldnames)
    # reorder the header first
    writer.writeheader()
    for row in csv.DictReader(infile):
        # writes the reordered rows to the new file
        writer.writerow(row)

对于以下输入：

ID, Text_1, Points_1, Text_2, Points_2
1, "Hello world one", 33, "Hello world two", 90
2, "Goodbye world one", 44, "Goodbye world two",100

上述程序将输出：

ID, Text_1, Text_2, Points_1, Points_2
1, "Hello world one", "Hello world two", 33, 90
2, "Goodbye world one", "Goodbye world two", 44, 100