python - 在 python 中添加额外的列以输出 csv 文件

Question

我目前在某些代码方面遇到了麻烦，我不太清楚如何使用 for 循环将年份(多个文件名的最后 4 位数字)添加为一种“ID”字段？我知道还有其他方法可以做到这一点，但我想尝试这种方法，因为我正在学习 for 循环。

我到目前为止的代码:

import csv

def extract_names(filename):

inF = open(filename, 'rU')
csvF = csv.reader(inFile, delimiter=',')


# Initialization
results = []
rowNum = 0

for row in  csvFile:

    if rowNum != 0:  #no need for first row#

        #This is where the results list is appended #

        records.append((row[0], row[1], "Boy")) 
        records.append((row[2], row[3], "Girl"))  





    rowNum += 1

inF.close()
return(results)



#### Start main program  #####

filenames = ('file2010.csv',     
'file2011.csv',
'file2012.csv', 
'file2013.csv',   
'file2014.csv')

outF = open('fileAll.csv','wb') 
csvF_out = csv.writer(outFile, delimiter=',')

for filename in filenames:
name, ext = filename.split('.')
year = name[-4:]     
results = extract_names(filename)




for line in results:
    line.insert(0,year)

print("Write in csv file...")     

outF.close()

期望的输出:

2010 | Y | X | Z

Answer 1

import csv
filenames = (
    'file2010.csv',     
    'file2011.csv',
    'file2012.csv', 
    'file2013.csv',
    'file2014.csv'
)

outF = open('fileAll.csv', 'wb') 
csvF_out = csv.writer(outF, delimiter=',')

def extract_content(filename):
    return [("0","1","boy"),("2","3","girl")]

for filename in filenames:
    name, ext = filename.split('.')
    year = name[-4:]     
    result = extract_content(filename)
    for row in result:
        csvF_out.writerow((year,)+row)

outF.close()


#  fileall.csv:
# 2010  | x |   y | z
# 2011  | x |   y | z
# 2012  | x |   y | z
# 2013  | x |   y | z
# 2014  | x |   y | z

哪里|代表一个新列。请注意，代码不是在循环外部使用 csv.writerows，而是在 for 循环内部使用 csv.writerow。不需要额外的循环。