Remove spaces before newlines

Question

I need to remove all spaces before the newline character throughout a string.

string = """
this is a line       \n
this is another           \n
"""

output:

string = """
this is a line\n
this is another\n
"""

Answer 1

You can split the string into lines, strip off all whitespaces on the right using rstrip, then add a new line at the end of each line:

''.join([line.rstrip()+'\n' for line in string.splitlines()])

Answer 2

import re
re.sub('\s+\n','\n',string)

Edit: better version from comments:

re.sub(r'\s+$', '', string, flags=re.M)