[帮助]从csv文件和output txt(python)中提取[帮助]

Question

enter image description here

I read the file 'average-latitude-longitude-countries.csv' to the Southern Hemisphere.

Print the country name of the country in the file 'result.txt'

Question:

I want you to fix it so that it can be printed according to the image file.

infile = open("average-latitude-longitude-countries.csv","r")
outfile = open("average-latitude-longitude-countries.txt","w")
joined = []
infile.readline()
for line in infile:
  splited = line.split(",")
  if len(splited) > 4:
    if float(splited[3]) < 0:
      joined.append(splited[2])
      outfile.write(str(joined) + "\n")
  else:
    if float(splited[2]) < 0:
      joined.append(splited[1])
      outfile.write(str(joined) + '\n')

Answer 1

It's hard without posting a head/first few lines of the CSV However, assuming your code works and the countries list is successfully populated. Then, you can replace the line

outfile.write(str(joined) + '\n')

with:

outfile.write("\n".join(joined))

OR

with those 2 lines:

for country in joined:
    outfile.write("%s\n" % country)

Keep in mind, those approaches just do the job. however, not optimum

Extra hints:

you can have a look at csv module of standard Python. can make your parsing easier

Also, splited = line.split(",") can lead to wrong output, if there a single quoted field that contains ",". like this: field1_value," field 2,value ",field3, field4, ...

Update: Now I got you, First of all you are dumping the whole aggregated array to the file for each line you read. you should keep adding to the array in the loop. then after the whole loop, dump in once (Splitting the accumulated array like above)

Here is your code slightly modified:

infile = open("average-latitude-longitude-countries.csv","r")
outfile = open("average-latitude-longitude-countries.txt","w")
joined = []
infile.readline()
for line in infile:
  splited = line.split(",")
  if len(splited) > 4:
    if float(splited[3]) < 0:
      joined.append(splited[2])
      #outfile.write(str(joined) + "\n")

  else:
    if float(splited[2]) < 0:
      joined.append(splited[1])
      #outfile.write(str(joined) + '\n')


outfile.write("\n".join(joined))