Sort the unsorted text file and rewrite to same text file in sorted order

sort -nk4 file

-n for numerical sort
-k for providing key

sort -nrk4 file

one = open("sample-r1.txt",'r')
two = open("sample-r2.txt",'r')
k=[]
h=[]
for line in one:
    tmp=line.rstrip().split('\t')
    if len(tmp)>1:
        k.append ( tmp )
for record in two:
    tmp=record.rstrip().split('\t')
    if len(tmp)>1:
        h.append ( tmp )
i=0
j=0
newList=[]
while i < len(k) and j < len(h):
    if k[i][1] <= h[j][1]:
        newList.append(k[i])
        i+=1
    else:
        newList.append(h[j])
        j+=1
while i < len(k):
    newList.append(k[i])
    i+=1
while j < len(h):
    newList.append(h[j])
    j+=1
for row in newList:
    print("\t".join(row))

 with open("file 1.txt", 'r') as f1, open("file 2.txt", 'r') as f2,open("file 3.txt", 'r') as f3:
    with open("outfile.txt", 'w') as o:

       files    = [f1,'b',f2,'b',f3]

       for i in files:

           if i != 'b':
              lines = i.readlines()
           else:
              lines = '\n'

           o.writelines(lines)

file 1 line 1
file 1 line 2
file 1 line 3file 2 line 1
file 2 line 2
file 2 line 3file 3 line 1
file 3 line 2
file 3 line 3

f  = open("outfile.txt",'r')
print(f.read())

file 1 line 1
file 1 line 2
file 1 line 3
file 2 line 1
file 2 line 2
file 2 line 3
file 3 line 1
file 3 line 2
file 3 line 3