how to sort data inside text file in accending order in python?-CodePudding

I have a text file containing number integer and string value pairs I want to sort them in ascending order but I am not getting it correct

**TextFile.txt **

87,Toronto
45,USA
45,PAKISTAN
33,India
38,Jerry
30,Tom
23,Jim
7,Love
38,Hate
30,Stress

My code

def sort_outputFiles():
    print('********* Sorting now **************')
    my_file = open("TextFile.txt", "r",encoding='utf-8')
    data = my_file.read()
    data_into_list = data.split("\n")
    my_file.close()
    score=[]
    links=[]
    for d in data_into_list:
        if d != '':
            s=d.split(',')
            score.append(s[0])
            links.append(s[1])
    n = len(score)
    for i in range(n):
        for j in range(0, n-i-1):
            if score[j] < score[j 1]:
                score[j], score[j 1] = score[j 1], score[j]
                links[j], links[j 1] = links[j 1], links[j]

    for l,s in zip(links,score):
        print(l," ",s)

My output

********* Sorting now **************
Toronto   87
Love   7
USA   45
PAKISTAN   45
Jerry   38
Hate   38
India   33
Tom   30
Stress   30
Jim   23

Expected output

********* Sorting now **************
Toronto   87
USA   45
PAKISTAN   45
Jerry   38
Hate   38
India   33
Tom   30
Stress   30
Jim   23
Love   7

having error at line 2 in out put it should be in last

CodePudding user response：

You are comparing strings, not numbers.

In an dictionary (like, the physical book), the words are sorted by who has the "lowest" first letter, and if it's a tie, we pick the lowest second letter, and so on. This is called lexicographical order.

So the string "aaaa" < "ab". Also, "1111" < "12"

To fix this, you have to convert the string to a number (using int(s[0]) instead of s[0] in the score.append function).

This will make 1111 > 12. Your code will give the correct result.

CodePudding user response：

You can use Python's sorted() function to sort the list. If you use the key parameter, you can specify a custom sorting behaviour, and if you use the reverse parameter, you can sort in descending order.

Also, you can use the csv module to make reading your input file easier.

import csv

with open("TextFile.txt", "r", encoding="utf-8", newline="") as csvfile:
    lines = list(csv.reader(csvfile))
for line in sorted(lines, key=lambda l: int(l[0]), reverse=True):
    print(f"{line[1]} {line[0]}")

Output:

Toronto 87
USA 45
PAKISTAN 45
Jerry 38
Hate 38
India 33
Tom 30
Stress 30
Jim 23
Love 7

CodePudding user response：

Not sure about your intentions, but a compact implementation would be like:

with open('textfile.txt', 'r') as f:
    d = [l.split(',') for l in f.readlines()]
d=[(dd[1][:-1], int(dd[0])) for dd in d]
d_sorted = sorted(d, key=lambda x:x[1], reverse=True)
print(d_sorted)