Python中for循环选项的结尾？

Question

What else can I do at the end other than printing this out to a file? I don't know any other way to end a for loop and I don't want to have unnecessary files all over the place. As an example:

data = open(filename, "r")
found = open("Found.txt", "w")

for line in data:
    if re.match("(.*)(background-color:red)(.*)", line):
        print >> found, line,

I don't WANT to save found at the end...but I don't know how else to take the matched data and do anything with it. I've been beating my face on the desk for hours, searched all over the place and I have no idea. Seems so basic...lol

Please help...

Answer 1

Use break to exit from a loop. And why do you need an output file? (by the way: that's not the correct way to write to a file). Just print the line, if that's what you intend:

for line in data:
    if re.match("(.*)(background-color:red)(.*)", line):
        print line
        break

Or save the line in a variable, for using it later. This really depends on what your program is supposed to do, and whether the results of the match need to be persisted for future reference, or if it's enough to save them in-memory for further processing:

result = None

for line in data:
    if re.match("(.*)(background-color:red)(.*)", line):
        result = line
        break

if result:
    # do something with `result`
    pass