正则表达式解析字符串

Question

I have potential strings like this. The fist few characters are a symbol that can be one to a few letters, but could contain weird characters like "/". Then the next six characters are always a date , YYMMDD where YY,MM,DD are always integers , but are always padded to the left with a 0 as shown. This is followed by a single character that is always 'C' or 'P', then finally a double .

AAPL220819C152.5
AAPL220819P195
AAPL220902P187.5
AAPL220819C155
AAPL220930C180

What is a regular expression that parses these strings into its constituent parts,

Symbol,
Date,
COP,
Strike

fast ?

So the expected output would be:

"AAPL220819C152.5" {Symbol = "AAPL", Date = 2022-08-19, COP = "C", Strike = 152.5 }
"AAPL220819P195"   {Symbol = "AAPL", Date = 2022-08-19, COP = "P", Strike = 195.0}

I have seen similar posts here but I don't understand enough to modify it.

Answer 1

Try this:

        static void Main(string[] args)
        {
            TestParsingRegex("AAPL220819C152.5", "AAPL220819P195", "AAPL220902P187.5", "AAPL220819C155", "AAPL220930C180");
        }

        private static void TestParsingRegex(params string[] strings)
        {
            var regex = new Regex(@"([A-Z]+)(\d{6})([CP]{1})(.*)");
            foreach (var s in strings)
            {
                var match = regex.Match(s);
                foreach (var g in match.Groups)
                {
                    Console.WriteLine(g);
                }
            }
        }

it should have the following output:

AAPL220819C152.5
AAPL
220819
C
152.5
AAPL220819P195
AAPL
220819
P
195
AAPL220902P187.5
AAPL
220902
P
187.5
AAPL220819C155
AAPL
220819
C
155
AAPL220930C180
AAPL
220930
C
180

Notice that the first group is the entire string

This regex uses groups to get the desired parsing like so:

([AZ]+) all upper case letters up to the next group

(\d{6}) exactly six digits

([CP]{1}) exactly one C or P character

(.*) everything else