Python：如何在CSV文件中求和，而仅求和某个变量的整数？

Question

I'm trying to program some data in a csvfile by using Python. I have a list of countries and results of the Eurovision Songcontest, and it looks like this:

Country,Points,Year
Belgium;181;2016
Netherlands;153;2016
Australia;511;2016
Belgium;217;2015
Australia;196;2015

Et cetera.

In summary, I want to sum the total of points that any country received throughout the years, so the output should look something like this: 'Belgium: 398','Netherlands: 153','Australia: 707' and so on.

This is what my code looks like:

import csv
with open('euro20042016.csv', 'r') as csvfile:
    pointsallyears = []
    countriesallyears = []
    readFILE = csv.reader(csvfile, delimiter=';')
    for row in readFILE:
        countriesallyears.append(row[0])
        pointsallyears.append(row[1])
csvfile.close()

results = []
for result in pointsallyears:
    result = int(result)
    results.append(result)

scorebord = zip(countriesallyears,results)

So I already made sure that the results / points are actual integers and I filtered out the third row (Year), but I have no idea how to proceed from here. Thanks a lot in advance!

Answer 1

Just put @Mikk's comment into an actual answer. Two lines except the import

import pandas as pd
df = pd.read_csv('euro20042016.csv', sep = ';')
print df.groupby('Country')['Points'].sum()

The only extra thing you need to do is to change the first line of your file to be delimited by ; instead of , .

Answer 2

I slightly changed your code to use a dictionary and used country names as keys. In result dictionary d will have country names as key and value is the total points.

import csv

d = dict()

with open('euro20042016.csv', 'r') as csvfile:
    readFILE = csv.reader(csvfile, delimiter=';')
    print (readFILE)
    c_list = []
    for row in readFILE:
        if row[0] in c_list:
            d[row[0]] = d[row[0]] + int(row[1])
        else:
            c_list.append(row[0])
            d[row[0]] = int(row[1])
csvfile.close()

print(d)

Answer 3

I decided to play around a bit with your code, and this is what I came up with. Here, row[0] contains the country names, and row[1] contains the values we need. We check if the country already exists in the dictionary we use to maintain the aggregates, and if it doesn't we create it.

import csv
with open('euro20042016.csv', 'r') as csvfile:
score_dict={}
readFILE = csv.reader(csvfile, delimiter=';')
for row in readFILE:
    # Only rows with 3 elements have the data we need
    if len(row) == 3:
        if row[0] in score_dict:
            score_dict[row[0]]+=int(row[1])
        else:
            score_dict[row[0]]=int(row[1])
csvfile.close()
print score_dict

What I get as output is this

{'Belgium': 398, 'Australia': 707, 'Netherlands': 153}

which I believe is what you were aiming for.

Let me know in the comments if you face a problem understanding anything.

Answer 4

I have solution of that. but make sure your euro20042016.csv file same as

Belgium;181;2016
Netherlands;153;2016
Australia;511;2016
Belgium;217;2015
Australia;196;2015

and this code get output in list. like

[('Belgium', 398), ('Australia', 707), ('Netherlands', 153)]

Code is here

try:
    f = open('euro20042016.csv', 'r+')
    s = f.read()

    lst = list(map(lambda x: x.split(';'), s.split('\n')))

    points, country = [], []
    for line in lst:
        points.append(int(line[1]))
        country.append(line[0])

    countrypoints = sorted(zip(country, points), key=lambda x: x[1])
    country = list(set(country))
    total = [0]*len(country)

    for rec in countrypoints:
        total[country.index(rec[0])] = total[country.index(
            rec[0])] + rec[1]
    f.close()
    finalTotal = list(zip(country, total))
    print finalTotal

except IOError as ex:
    print ex
except Exception as ex:
    print ex

I hope this will help you.