Python .csv编写器

Question

I use a .writer() method in a loop, as shown in the Python documentation. I want to write the results of the variable u , row by row (or better line by line).

Actually it works perfectly in the interpreter but the module writerow() doesn't seem to work. Why?

from urlparse import urlparse
import csv
import re

ifile =open(ipath,'r')
ofile = open(opath, 'wb')
writer = csv.writer(ofile, dialect='excel')

url =[urlparse(u).netloc for u in file (ipath, "r+b")]
sitesource =  set([re.sub("www.", "", e) for e in url])
liste = [re.split(",'", e) for e in liste]


ofile
for row in file (ifile) :
    for u in sitesource:
        print ("Creation de:", u)
        writer.writerow(u) 

ofile.close()

I'm using Python 2.7.

Answer 1

Guessing at you really mean, I would rewrite your code as follows:

from urlparse import urlparse
import csv
import re

ifile =open(ipath,'r')
ofile = open(opath, 'wb')
writer = csv.writer(ofile, dialect='excel')

url =[urlparse(u).netloc for u in ifile]
sitesource =  set([re.sub("www.", "", e) for e in url])

for u in sitesource:
    print ("Creation de:", u)
    writer.writerow([u]) 

ofile.close()
ifile.close()

I deleted liste as it's not used. I got rid of for row in file (ifile): as you already iterated over its contents when you created url .

I changed

url =[urlparse(u).netloc for u in file (ipath, "r+b")]

to

url =[urlparse(u).netloc for u in ifile]

because you already had the file open. I assumed you did not want binary mode if you are reading strings.

I changed writerow(u) to write a sequence: writerow([u]) . This puts a single u per line, which means your csv file will not acutally have any commas in it. If you wanted all of your results in a single row, replace the final loop with this statment writer.writerow(sitesource) .

Answer 2

writerow()需要一个序列参数，所以我认为您需要使用writer.writerow([u])因为每个u是一个字符串-否则，您将按照目前的方式将一系列字符传递给它。

Answer 3

Are you trying to write the string "u"? or the contents of the variable ? If it's the latter option, then remove the parentheses.

Answer 4

不确定，但是csv.writer.writerow想要一个包含整个行字段的序列（我总是将其与列表一起使用），并且您正在遍历一组返回u中的内容的内容？