ANSWER IN PYTHON

A line from an input file has 4 fields with the following expected format: Field 1: A string that has one or more characters, none of which are double quotes. The string itself is enclosed within double quotes. Field 2: A real number with at least one digit before the decimal point with no leading zeros, and at least one digit after the decimal point. Field 3: A categorical value with the following possibilities: A, B+, B, C+, C, D Field 4: An integer between 1 and 999, no leading zeros.

Fields are separated by a comma. There may be spaces before and after a comma, and spaces around the entire line.

Here's an example:

"abcxy#$.,?PQR", 235.6614,B+,921

Write a regular expression to match and extract all 4 fields from a line of input. The extracted first field must include the surrounding double quotes characters. Assume that there will be a call re.findall that will apply your regular expression to a line string. If there are fewer or more than 4 fields, the regular expression should not match the string.