filtering files using 'any()"

[bowlofred]

The files are big and many, I do not want to do 'readlines' and if I'll do open each file then it is like doing 'for' loop, and I do not need 'any()'

I thought I can test each file as a whole file without checking each line.

Thank you.

If the files aren't large, you can just read the entire file into a string and then check if you have a string match. There is no loop necessary.

with open(filename, "r") as f:
    if matchstring in f.read():
        ...

But if the files are large, you don't want to load in the entire file into a single string. That implies that you will need to loop over chunks of the file. If it's a "sane" text file, you can assume newlines every so often and let the file iterator hand you one line at a time. Loop over each and exit when you get your first match. any() would be nice about doing that.

with open(filename, "r") as f:
    # f is the file iterator.  The expression inside the parens is a generator comprehension, so
    # the entire file is not read into memory, just each line is matched.  any() will exit after any
    # match is successful and doesn't have to read the rest of the file.
    if any(matchstring in line for line in f):
        ...