Python write in the same line of file

Question

Supose i have a function like this:

f=open('file.txt','w')
n=0
while(n<20):
    f.write(n)
    n=n+1
f.close()

but the loop writes all numbers to the file, and i just want the current number in the loop

example:

1234567891011121314151617181920

Answer 1

with open('file.txt', 'w') as f:
    for n in range(20):
        f.write(str(n) + '\n')

alternatively:

with open('file.txt', 'w') as f:
    for n in range(20):
        print(n, file=f)