Added headers everywhere and added a missing newline

Lesson_2/task4.py

@@ -17,4 +17,4 @@ if not error:
 	else:
 		print(str(number) + " factorial is " + str(factorial))
 else:
-	print("Invalid number entered.")
+	print("Invalid number entered.")

Lesson_3/We know/bank_card.py

@@ -1,3 +1,10 @@
+# Lesson 3 Task K3F9#@%^&?: bank card validation
+# Author: Stanislav Mykhailenko
+# License: Unlicense
+
+# Return codes:
+# 0 - OK
+
 def validateLength(number):
 	if len(number) < 13 or len(number) > 16 or len(number) == 14:
 		return False
@@ -34,4 +41,3 @@ if validateLength(number) and validateLuhn(number):
 		print("INVALID")
 else:
 	print("INVALID")
-

Lesson_5/Task 2/webserver.py

@@ -1,3 +1,7 @@
+# Lesson 5 Task 2: web calculator
+# Author: Stanislav Mykhailenko
+# License: Unlicense
+
 from flask import Flask, render_template, redirect, request
 from datetime import datetime
 

Lesson_5/Task 3/webserver.py

@@ -1,3 +1,7 @@
+# Lesson 5 Task 3: web blog
+# Author: Stanislav Mykhailenko
+# License: Unlicense
+
 from flask import Flask, render_template, redirect, request
 from datetime import datetime
 

Lesson_5/Task 4/webserver.py

@@ -1,3 +1,7 @@
+# Lesson 5 Task 4: web blog with admin
+# Author: Stanislav Mykhailenko
+# License: Unlicense
+
 from flask import Flask, render_template, redirect, request
 from flask_httpauth import HTTPBasicAuth
 from werkzeug.security import generate_password_hash, check_password_hash

Lesson_6/Task 1/webserver.py

@@ -1,3 +1,7 @@
+# Lesson 6 Task 1: web chat
+# Author: Stanislav Mykhailenko
+# License: Unlicense
+
 from databaseWorker import *
 from flask import Flask, render_template, redirect, request
 

Lesson_6/Task 2/webserver.py

@@ -1,3 +1,7 @@
+# Lesson 6 Task 2: web server system info
+# Author: Stanislav Mykhailenko
+# License: Unlicense
+
 from databaseWorker import *
 from flask import Flask, render_template, redirect, request
 import platform, psutil, os

Lesson_7/Task 1/webserver.py

@@ -1,3 +1,7 @@
+# Lesson 7 Task 1: web page image download
+# Author: Stanislav Mykhailenko
+# License: Unlicense
+
 from bs4 import BeautifulSoup
 from flask import Flask, render_template, request, send_from_directory
 from zipfile import ZipFile