add coments on export

export.py

+# to run this script and export the database from an docker container run docker -it <container_name> python3 export.py > database.csv
+#The output will be in excel-style CSV (";" instead of "," as column seperator.)
+
 import sqlite3
 
 create_table = """
@@ -8,7 +11,7 @@ create_table = """
     """
 with sqlite3.connect('db/urls.db') as conn:
     cursor = conn.cursor()
-    try: #Try making the database structure, if fails Database was already created.
+    try: #Try making the database structure, if succeeded, exit, because there can't be any data.
         cursor.execute(create_table)
         print("No data Found, exiting")
         exit()
@@ -17,6 +20,6 @@ with sqlite3.connect('db/urls.db') as conn:
 
 conn = sqlite3.connect('db/urls.db')
 cursor = conn.cursor()
-res = cursor.execute('SELECT LONG_URL, SHORT_URL FROM WEB_URL WHERE 1')
+res = cursor.execute('SELECT LONG_URL, SHORT_URL FROM WEB_URL WHERE 1') #read all data from database
 for entries in res.fetchall():
-    print(str(entries[1]) + ";" + str(entries[0]))
+    print(str(entries[1]) + ";" + str(entries[0])) #format the data and print it to console.
\ No newline at end of file