Sorting txt lines numerically

Question

I took txt file as input and i want to sort them numerically. How can i do? The input file as txt:

65 1 Hello
78 3 up
78 2 what's
65 2 world

i want the output as:

message 1:
    65 1 Hello
    65 2 world
message 2:
    78 2 what's
    78 3 up

First i need to sort first numbers, then i need to sort second numbers. I thought i can put every line in a list and then sort them. Then i need to write "message n:" before every text group. Finally i need to put them in a new txt file.

Answer 1

you can use List.sorted:

# Using readlines() 
file1 = open('./mytext.txt', 'r') 
Lines = file1.readlines() 
  

Lines.sort(key=lambda line: (int(line.split(" ")[0]),int(line.split(" ")[1])),reverse=False)


print(Lines)



temp=0
count=0
for i in Lines:
    value = int(i.split(" ")[0])
    if(value!=temp):
        count+=1
        print("message {0}:".format(count))
        print("    "+(i).replace("\n",""))
        temp=value
    else:
        print("    "+(i).replace("\n",""))
        temp=value
        

Output

IF you have to sort first in descending order using first-row value and then in ascending using the second-row value

This can be done by assigning negative to the second number

# Using readlines() 
file1 = open('./mytext.txt', 'r') 
Lines = file1.readlines()   

Lines.sort(key=lambda line: (int(line.split(" ")[0]),-int(line.split(" ")[1])),reverse=True)
    
print(Lines)    

temp=0
count=0
for i in Lines:
    value = int(i.split(" ")[0])
    if(value!=temp):
        count+=1
        print("message {0}:".format(count))
        print("    "+(i).replace("\n",""))
        temp=value
    else:
        print("    "+(i).replace("\n",""))
        temp=value

Output:

Answer 2

You can sort them after splitting into separate lines by 1st and second order numbers as:

sorted([line.split() for line in file_contents.split('\n')], key = lambda x:(int(x[0]), int(x[1])))

results in:

[['65', '1', 'Hello'],
 ['65', '2', 'world'],
 ['78', '2', "what's"],
 ['78', '3', 'up']]

Then you can play around with this list to have output to your liking: Hint. Go grab the unique 0th index values and change the message number when 0th index is changed. While it is unchanged concat all 2nd index values.