nsl_class.py

from datetime import datetime
import re

# Structured NSL Data
class NSL:
    @staticmethod
    def create_from_csv_line(csv_line):
        issue_date, release_date, company, nsl_file_number, link_to_nsl_file, comment = csv_line.split(",")
        issue_date = NSL.parse_strftime(issue_date)
        release_date = NSL.parse_strftime(release_date)
        return NSL(issue_date, release_date, company, nsl_file_number, link_to_nsl_file, comment)

    @staticmethod
    def format_datetime(timestamp):
        return timestamp.strftime('%Y-%m-%d')

    @staticmethod
    def parse_strftime(timestamp_str):
        """
        Parse string as datetime instance
        """
        return datetime.strptime(timestamp_str, '%Y-%m-%d')
    

    @staticmethod
    def parse_file_number(file_name):
        """
        parse the NSL file number out of an NSL file name
        """
        match = re.search(".*NSL-\d+-(\d*[\s(a-zA-Z)]*[-\d]*)[\._]?.*", file_name)
        if match:
            file_number_str = match.group(1)
            return file_number_str, NSL.file_str_to_numbers(file_number_str)
    
    @staticmethod
    def file_str_to_numbers(file_number_str):
        """
        Some files have letters like (a) or (b) after their number,
        we parse them and add this as a fraction to the file number to
        disambiguate letters.
        """

        if type(file_number_str) in [int, float]:
            return float(file_number_str)
        
        # Case: 34567(a)
        if "(" in file_number_str:
            nsl_file_number_parts = file_number_str.split("(")
            nsl_file_number_float = float(nsl_file_number_parts[0])
            letter_fraction = (ord(nsl_file_number_parts[1][:-1]) - ord("a"))/26
            nsl_file_number_float += letter_fraction
        # Case 34567-1
        elif "-" in file_number_str:
            nsl_file_number_parts = file_number_str.split("-")
            nsl_file_number_float = float(nsl_file_number_parts[0])
            letter_fraction = int(nsl_file_number_parts[1])/10
            nsl_file_number_float += letter_fraction
        # Standard case: 34567
        else:
            nsl_file_number_float = float(file_number_str)

        return nsl_file_number_float
    
    @staticmethod
    def export_nsls_as_csv(nsls, csv_file_path):
        with open(csv_file_path, "w") as csv_file:
            csv_file.write("issue date,release date,company,file number,url,comment\n")
            for nsl in nsls:
                csv_file.write(nsl.export_as_csv_line() + "\n")

    def __init__(self, issue_date, nsl_file_name, year=None, company=None, release_date=None, link_to_nsl_file=None, link_to_release_letter=None, comment=None):
        self.issue_date = issue_date
        self.nsl_file_number, self.nsl_file_number_float = NSL.parse_file_number(nsl_file_name)
    
        # The following are not available for all NSLs
        self.company = company
        self.year = year  
        self.release_date = release_date
        self.link_to_nsl_file = link_to_nsl_file
        self.link_to_release_letter = link_to_release_letter
        self.comment = comment

    def __repr__(self):
        return self.__str__()

    def __str__(self):
        return f"NSL({self.nsl_file_number}, {self._format_datetime(self.issue_date)})"
    
    def export_as_csv_line(self):
        """
        Format: issue date, release date, company, file number, url, comment
        """
        line_data = [NSL.format_datetime(self.issue_date), NSL.format_datetime(self.release_date), self.company, self.nsl_file_number, self.link_to_nsl_file, self.comment]
        line_data_filtered = [entry if entry != None else "" for entry in line_data]
        return ",".join(line_data_filtered)