Python，数据重传

Question

我有如下数据

id,Stage1Pow1,Stage1Pow2,Stage2Pow1,Stage2Pow2
A,1.0,1.5,1.1,1.4
B,0.9,1.2,0.9,1.1
C,1.0,1.0,0.8,0.8

如何将它们转换为以下格式，以便按阶段存储和进一步分析

id,StageNo,Pow1,Pow2
A,s1,1.0,1.5
A,s2,1.1,1.4
B,s1,0.9,1.2
B,s2,0.9,1.1
C,s1,1.0,1.0
C,s2,0.8,0.8

我对Python很陌生

Answer 1

输入文件名为'raw'，输出文件名为'output'

import csv

data = []
with open('raw', 'r') as f:
    csvreader = csv.reader(f, delimiter=',')
    for row in csvreader:
        data.append(row)

with open('output', 'w') as f:
    csvwriter = csv.writer(f)
    csvwriter.writerow(['id', 'StageNo', 'Pow1', 'Pow2'])
    for row in data[1:]:
        csvwriter.writerow([row[0], 's1', row[1], row[2]])
        csvwriter.writerow([row[0], 's2', row[3], row[4]])

有关https://docs.python.org/2/library/csv.html的详细信息

Answer 2

您可以使用csv模块csv.DictReader()和csv.DictWriter()

import csv
with open('input.csv','r') as file:
    reader = csv.DictReader(file)
    with open('output.csv','w') as file_output:
        writer = csv.DictWriter(file_output,fieldnames=['id','StageNo','Pow1','Pow2'])
        writer.writeheader()
        for line in reader:
            line_split1 = {'id':line['id'],'StageNo':'s1','Pow1':line['Stage1Pow1'],'Pow2':line['Stage1Pow2']}
            line_split2 = {'id':line['id'],'StageNo':'s2','Pow1':line['Stage2Pow1'],'Pow2':line['Stage2Pow2']}
            writer.writerows([line_split1,line_split2])

输出：

id,StageNo,Pow1,Pow2
A,s1,1.0,1.5
A,s2,1.1,1.4
B,s1,0.9,1.2
B,s2,0.9,1.1
C,s1,1.0,1.0
C,s2,0.8,0.8