import re


def number_increment(line):
    """
    Take a string of form: text 10
    Parse the number part, increment it by 1 and return the original string with new number.

    Returns: The new string with number portion incremented.
    """
    match = re.search(r'\d+', line)
    if not match:
        raise ValueError("number_increment: line did NOT contain a parsable integer.")

    old_num = int(match.group(0))
    return line.replace(str(old_num), str(old_num + 1))