Why there's a 'blank line' on CSV file?

[snippsat]

If i just copy some of your data,then doing some stuff to get it in a list data structure.
You can append to list so get similar structure,then it easy to write to csv.

import csv

data = '''\
23/03/2021 09:09    50  18  34  1
23/03/2021 09:09    50  18  34  1
23/03/2021 09:09    50  19  34  1
23/03/2021 09:09    50  19  34  1'''

lst = data .split('\n')
lst = [i.split() for i in lst]
print(lst)

with open("out.csv", "w", newline="") as f:
    writer = csv.writer(f)
    writer.writerows(lst)

Output:
[['23/03/2021', '09:09', '50', '18', '34', '1'],
 ['23/03/2021', '09:09', '50', '18', '34', '1'],
 ['23/03/2021', '09:09', '50', '19', '34', '1'],
 ['23/03/2021', '09:09', '50', '19', '34', '1']]

# out.csv
23/03/2021,09:09,50,18,34,1
23/03/2021,09:09,50,18,34,1
23/03/2021,09:09,50,19,34,1
23/03/2021,09:09,50,19,34,1