# Import Python's system functionality module for the exit function when passwords are wrong
import sys

# Import Python's regular expressions library, popularly known as Regex
import re


# Prompt the user to enter their userName, the userName input will be type converted to str
userName = str(input("\n\tPlease input your username: \n\n\t"))

# Print a welcome message string formated to includ the username
print("\n\t Welcome:  {}\n".format(userName))

# Prompt the user to enter a passWord, input will be type converted to str for regex manipulation
passWord = str(input("\n\tPlease enter a password.\n\n\t Type here: "))


# Test to see whether the user enters a series of comma separated passWords
# Do this by testing the passWord string for the presence of a comma
# If there's a comma in the passwords sequence, split up the string by comma
if "," in passWord:

	# Create a list called passWordsList that will hold the passWords
	passWordsList = passWord.split(",")

	# The passWord is the value in passWordsList[0]
	passWord = passWordsList[0]

# The invalidPassWordMessage string is to be printed on the screen if the password in invalid
invalidPasswordMessage = """
		Your password is invalid.The password must have:

		  1. At least 1 letter between [a-z]
		  2. At least 1 number between [0-9]
		  3. At least 1 letter between [A-Z]
		  4. At least 1 character from [$#@]
		  5. Minimum length of transaction password: 6
		  6. Maximum length of transaction password: 12

		"""

# Create a boolean test for the validity of the password, with value False
passwordTest = False
while passwordTest:

	# Using the regex library search method test if lower case letters are
	# present in the passWord string, the first arguement of the search method
	# is the pattern and the second arguement is the string to be tested
	if re.search("[a-z]", passWord) == False:
		# If the passWord string does not have lower case characters[a-z]
		# print the invalidPasswordMessage
		print("{}".format(invalidPasswordMessage))
		# Exit the application
		sys.exit()
	elif re.search("[0-9]", passWord) == False:
		# If the passWord string does not have any digit from [0-9]
		# print the invalidPasswordMessage
		print("{}".format(invalidPasswordMessage))
		# Exit the application
		sys.exit()
	elif re.search("[A-Z]", passWord) == False:
		# If the passWord string does not have upper case characters [A-Z]
		# print the invalidPasswordMessage
		print("{}".format(invalidPasswordMessage))
		# Exit the application
		sys.exit()
	elif re.search("[$#@]", passWord) == False:
		# If the passWord string does not have the special characters [$#@]
		# print the invalidPasswordMessage
		print("{}".format(invalidPasswordMessage))
		# Exit the application
		sys.exit()
	elif (len(passWord) < 6 or len(passWord)>12):
		# If the passWord string does not meet length specifications
		# print the invalidPasswordMessage
		print("{}".format(invalidPasswordMessage))
		# Exit the application
		sys.exit()
else:
	# If all the passWord conditions have been met, print the username and password
	print("\n\t {}, your password is: {}".format(userName, passWord))
	# Exit the application
	sys.exit()