import re
import io


def parse(text):
    last_name = ''
    result = []
    with_name = re.compile(r'^(\w+): (.*)')
    for line in text:
        match = with_name.search(line)

        if match:
            last_name = match.group(1)
            msg = match.group(2)
        else:
            msg += ' ' + line
            continue

        if last_name:
            result.append((last_name, msg))
    return result


def parse_files(files):
    result = []
    for file in files:
        with open(file) as fd:
            result += parse(fd)
    return result



def printer(parsed_data):
    for name, message in parsed_data:
        print(name, '->', message)


text = """Rich: I'm going to attend a concert on Saturday.
Do you have any special plans?
Peter: No, I'm going to relax. What did you do last weekend?
Rich: Last weekend, I went to visit my friends in San Francisco. What did you do?
Peter: I played soccer with some friends."""


out = parse(io.StringIO(text)) # using the string as a file
printer(out)

Output:
Rich -> I'm going to attend a concert on Saturday.
Peter -> No, I'm going to relax. What did you do last weekend?
Rich -> Last weekend, I went to visit my friends in San Francisco. What did you do?
Peter -> I played soccer with some friends.