在 Python 中以不同的顺序写入 CSV 列

Question

我意识到这与这个问题非常相似。 但是，我有一个 CSV 文件，它始终采用相同的格式，我需要以不同的顺序写出列，以将其移到数据处理管道中。 如果我的 csv 文件包含如下标题和数据：

Date,Individual,Plate,Sample,test,QC
03312011,Indiv098,P342,A1,deep,passed
03312011,Indiv113,P352,C3,deep,passed

我将如何写出与原始输入 csv 具有相同列但按以下顺序的 csv 文件：

test,QC,Plate,Sample
deep,passed,P342,A1
deep,passed,P352,C3

我最初的想法是做这样的事情：

f = open('test.csv')
lines = f.readlines()
for l in lines:
    h = l.split(",")
    a, b, c, d, e, f  = h
    for line in h:
        print e, f, c, d, 

Answer 1

reorderfunc = operator.itemgetter(4, 5, 2, 3)

 ...

newrow = reorderfunc(oldrow)
 ...

Answer 2

如果输入文件或 output 文件每次都不会具有相同的布局，那么这是获得“reorderfunc”的更通用方法：

writenames = "test,QC,Plate,Sample".split(",") # example
reader = csv.reader(input_file_handle)
writer = csv.writer(output_file_handle)
# don't forget to open both files in binary mode (2.x)
# or with `newline=''` (3.x)
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))

Answer 3

鉴于您的输入为src.csv ：

import csv

with open('x.csv','rb') as i:
    with open('y.csv','wb') as o:
        r = csv.DictReader(i)
        w = csv.DictWriter(o,'test QC Plate Sample'.split(),extrasaction='ignore')
        w.writeheader()
        for a in r:
            w.writerow(a)

Output

test,QC,Plate,Sample
deep,passed,P342,A1
deep,passed,P352,C3

Answer 4

#Use CSV library
import csv
media = {}
files=['Online.txt']
directory = "C:/directory/"
rowCnt=0

for file in files:

    file=directory+file

    with open(file, 'rb') as f:
        reader = csv.reader(f, delimiter='|') #use pipe delimiter

        for row in reader:
            rowCnt+=1
            if (rowCnt % 1000) == 0:
                print ('"%s","%s","%s","%s","%s","%s","%s","%s","%s"')% (row[1],row[4],row[14],row[17],row[18],row[24],row[25],row[28],row[30])