如何找到字符串的特定部分？

Question

Im accessing a csv file, looping through all of its rows(strings) and i want too keep / print all parts of each string which start with a ".", has two words in the middle and ends with either a "." "?" or ".".

For example, if the string was: "This is my new channel. Please subscribe." i'd only want to keep the ". Please subscribe!"

So far i only have this to show me how many words are inside each string:

with open("data2.csv", encoding="utf-8", newline='') as f:
    reader = csv.reader(f)
    for row in reader:
        rowstr = str(row[1])
        res = len(row[1].split())
        print(res)

I've tried:

with open("data2.csv", encoding="utf-8", newline='') as f:
    reader = csv.reader(f)
    for row in reader:
        rowstr = row[1]
        res = len(row[1].split())
        re.findall(r"\.\S+\s\S+[.?!]", rowstr)
        print(row[1])

I get no output from findall, only from printing row[1]

Fixed it

Working code:

with open("data2.csv", encoding="utf-8", newline='') as f:
    reader = csv.reader(f)
    for row in reader:
        rowstr = row[1]
        res = len(row[1].split())
        finalData = re.findall(r"(\.\W\w+\W\w+[\.\?!])", rowstr)
        print(finalData)

Answer 1

You can use regular expression:

re.findall(r'(\.\W\w+\W\w+[\.\?!])$',"This is my new channel. Please subscribe!" )

which output: ['. Please subscribe!'] ['. Please subscribe!']

Answer 2

Regex is the best solution to the problems like this. Please refer here here !