如何使用python对CSV文件进行排序并将排序后的数据写入新的CSV文件

Question

i have a sample csv file with me which contains some random numbers which are not sorted. i want to sort the data from the csv file and i have to write the sorted data into a new csv file. the problem is if i have a data like

 3,
65,
20,
21,
19,
34,
8,
0,
22

python is sorting based on the first digit only. if i print out the sorted data, i'm getting the below as output.

['0'], ['19'], ['20'], ['21'], ['22'], ['3'], ['34'], ['65'], ['8']

which is the sorting is performing based on the first digit.

and i want to write the sorted data to a new csv file.

thanks in advance.

Answer 1

You can use numpy to deal with type conversion. Something like this should work:

import numpy as np

arr = np.genfromtxt('in.csv', delimiter=',')
arr.sort()

np.savetxt('out.csv', arr, delimiter=',')

Answer 2

Given that you have optional whitespace and commas this should work:

with open('in.csv') as infile, open(out.csv) as outfile:
    data = infile.readlines() #read data into list line by line
    nums = [''.join([c for c in i if c.isdigit()]) for i in data] #extract only the numbers from lines
    result = sorted(nums, key=int) #sort the numbers by their integer value ascending (default)
    outfile.write(',\n'.join(result)) #write result to file adding `,\n` to end of each number - \n being the newline

Answer 3

import csv


with open('sample.csv') as file:
    reader = csv.reader(file)
    i = 0
    new_data = []
        for row in reader:
            if(row[0]!='' and row[0].isdigit()):
                new_data.append(row[0])
                new_data.sort(key=int)
                print(new_data)
with open('newfile.csv', 'w') as newfile:
    writer = csv.writer(newfile)
    writer.writerow(new_data)

the above code worked for me. thanks for all the contribution.