Basic Python 3 Win 10 Search Txt to File Newbie

[keames]

I think I understand what you want to do. Does this code produce a result to your liking?

# some named constants here so if you want to change these values, you don't need run around
# changing a bunch of hard-coded literals.
SOURCE_FILE_PATH = "C:\\Users\\John\Desktop\\StuffIn.txt"
DESTINATION_FILE_PATH = "C:\\Users\\John\Desktop\\StuffOut.txt"
SEARCH_TARGET = 'VisaRen'

# You want all the strings that contain your search target in your destination file, so we
# use a list and append everything to it.
matchedStrList = []
with open(SOURCE_FILE_PATH, "r") as f:
    # The readlines method returns a list with all the lines in the file, sans trailing 
    # newlines.
    for line in f.readlines():
        # list.append takes a single object as a parameter and puts it on the end of the list.
        if SEARCH_TARGET in line: matchedStrList.append(line)

with open(DESTINATION_FILE_PATH, "w") as f:
    # enumerate returns the tuple (index, value) where index is the index within the iterable
    # where the value appears. Using this syntax, we can unpack these two values into separate
    # variables
    for index, line in enumerate(matchedStrList):
        if index < len(matchedStrList) - 1:
            f.write(line + "\n")
        else:
            # Write the last item to the file without a trailing newline. (You can get rid of
            # this functionality if you want.)
            f.write(line)

I hope this solution helps. Python is for the most part, very well documented and there are a lot of tutorials available on many platforms. Don't be afraid to look around.