How can I include special characters (tab, newline) in a python doctest result string?

Question

Given the following python script:

# dedupe.py
import re

def dedupe_whitespace(s,spacechars=\'\\t \'):
    \"\"\"Merge repeated whitespace characters.
    Examp         


        

Answer 1

It's the raw heredoc string notation (r""") that did the trick:

# filename: dedupe.py
import re,doctest
def dedupe_whitespace(s,spacechars='\t '):
    r"""Merge repeated whitespace characters.
    Example:
    >>> dedupe_whitespace('Black\t\tGround')  #doctest: +REPORT_NDIFF
    'Black\tGround'
    """
    for w in spacechars:
        s = re.sub(r"("+w+"+)", w, s)
    return s

if __name__ == "__main__":
    doctest.testmod()