Python: ATM
From Mike Beane's Blog
I'm auditing part 1 of a Programming class in Python as I have to take part 2 next semester (I have an old transfer credit that covered Programming 1, alas the last time I did programming in school for school, it was in C and C++). I don't think I've ever done anything from start to finish in Python outside of print ("Hello world!"), though I've looked at the code of others a lot. My PERL programming comes in handy with this, but I'm still new at it.
It's a seven week course and one of the semester projects is to build an ATM prototype. I was out week one and I picked up the course notes a week ago (week 2). Tomorrow starts week 3.
To get through the project I had to figure out
- How Python works with lists
- This wasn't called for in the project, but it made things so much easier for the account setup.
- console output
- Why all the () stuff?
- if, elsif, else
- elif???
- casting types
- int\float, etc - I still have some basic trouble with this, mostly around remembering what I was hoping to do
- format output in columns
- not called for, I just don't like ugly columns
- functions
- I actually like Python's handling of functions, though I didn't look into passing information in an out, nor did I look into local vs global variables.
- Loops
- Made sense!
Here's my first iteration of the semester project, four days after I started it in IDLE:
#################################################################################
## /---------------------------------------------------------------------------\*
## | Program: ATM
## | Version: 0.0.1
## | Language: 3.7.4
## |
## | Description: ATM Project Iteration #1
## |
## | Course: IT 261-1
## | Author: Mike Beane
## \---------------------------------------------------------------------------/*
## Changelog
## Date Description
## ----- -------------
## 9/11/2019 Program Setup - Created Lists
## Basic account input created and sanity test
## 9/12/2019 Added PIN check (simple)
## 9/13/2019 Added WHILE LOOP screen clear: cls()
## 9/14/2019 Added Account # loop and testing to see if the
## value is in the list or not or input is
## valid by length.
## Added help() to list account variables (this
## is more for you than for me, it would NOT
## exist in a real program. Instead there
## would be Post-IT notes for this information.
## Updated PIN check (advanced and now with fail!)
## Created functions for repetitive things
## Added Deposit (simple) - needs sanity checks
## 9/15/2019 Updated Deposit checks
## Added Withdrawal routine and checks
#################################################################################
# Variables
debug = 1
PIN_Max_Attempts=3
#################################################################################
## System Variables - Do Not Edit Below This Line ###############################
#################################################################################
## Function - Clear Screen cludge
def cls():
i = 0
while i < 39: # Default window size seems to be 40 lines
print (" ") # Avoiding making sys() calls and just
i += 1 # Carriage returning the screen clear
## Function - Output Account Lists if "?" is used in the Account input section
def help():
cls()
print ("--------------------------------------------------------")
print ("|***************** Help: Account Info *****************|")
print ("--------------------------------------------------------")
print ("Account Pin Name ")
print ("--------------------------------------------------------")
i=0
while i < len(accounts):
print (""+accounts[i]+" "+pins[i]+" "+users[i])
i += 1
print (" ")
print (" ")
print ("** Realistically this wouldn't be here **")
print ("--------------------------------------------------------")
def header():
cls()
print ("--------------------------------------------------------")
print (" Name Account ")
print ("--------------------------------------------------------")
print (" "+users[account_position]+" "+User_Account)
print ("--------------------------------------------------------")
def main_menu():
print ("--------------------------------------------------------")
print ("Options: ")
print (" 1. Fund Balance Inquiry")
print (" 2. Deposit")
print (" 3. Withdraw ")
print (" 4. Quit")
print ("--------------------------------------------------------")
def balance_display():
print ("--------------------------------------------------------")
print ("Balance: ")
print (" Checking: $"+ str(BALANCE_Checking))
print (" Savings [1]: $"+ str(BALANCE_Savings_1))
print (" Savings [2]: $"+ str(BALANCE_Savings_2))
print ("--------------------------------------------------------")
def ledger():
table_data = [
# https://docs.python.org/2.7/library/string.html#format-specification-mini-language
# https://stackoverflow.com/questions/9989334/create-nice-column-output-in-python
[' ', 'STARTING','TOTAL','TOTAL','ENDING'],
['TYPE', 'BALANCE','DEPOSITS','WITHDRAWLS','BALANCE'],
['----------','----------','----------','----------','----------'],
['Checking', str(STARTING_BALANCE_CHECKING), DEPOSIT_TALLY_CHECKING, WITHDRAWAL_TALLY_CHECKING, BALANCE_Checking],
['Savings[1]', str(STARTING_BALANCE_Savings_1), DEPOSIT_TALLY_SAVINGS_1, WITHDRAWAL_TALLY_SAVINGS_1, BALANCE_Savings_1],
['Savings[2]', str(STARTING_BALANCE_Savings_2), DEPOSIT_TALLY_SAVINGS_2, WITHDRAWAL_TALLY_SAVINGS_2, BALANCE_Savings_2],
['----------','----------','----------','----------','----------'],
['TOTALS','',DEPOSIT_TALLY_CHECKING+DEPOSIT_TALLY_SAVINGS_1+DEPOSIT_TALLY_SAVINGS_2,WITHDRAWAL_TALLY_CHECKING+WITHDRAWAL_TALLY_SAVINGS_1+WITHDRAWAL_TALLY_SAVINGS_2,'',]
]
for row in table_data:
print("{: >10} {: >10} {: >10} {: >10} {: >10}".format(*row))
def startup():
cls()
print ("--------------------------------------------------------")
print ("--------------------------------------------------------")
print ("-------A.T.M.-------------------------------------------")
print ("---------NOTE: All Input Via Numeric Keypad-------------")
print ("--------------------------------------------------------")
print ("|************| |************|")
print ("|************| [ 7 ] [ 8 ] [ 9 ] |************|")
print ("|************| |************|")
print ("|************| [ 4 ] [ 5 ] [ 6 ] |************|")
print ("|************| |************|")
print ("|************| [ 1 ] [ 2 ] [ 3 ] |************|")
print ("|************| |************|")
print ("|************| [ 0 ] [ . ] [ ENTER ] |************|")
print ("|************| |************|")
print ("--------------------------------------------------------")
#################################################################################
## List Setup - User Accounts,Pins,Names
## Usage:
## List position dictates linkage between UA->Pin->Name
## Example: Entering 7654321 will match at position 3 below
## and will correspond with PIN 4567 and USER Hank Simpson
#################################################################################
## Ref: https://www.w3schools.com/python/python_arrays.asp
#### Python doesn't do Arrays
#### It does Lists. Let's do Lists
#################################################################################
accounts = ["1234567","8675309","6666666","7654321","5551212"]
pins = ["1234","2345","3456","4567","5678"]
users = ["Brock Shumway","Gale Winds","Gustavo Adolpho","Hank Simpsons","Hector Lizondo"]
total_accounts = len(accounts)
total_pins = len(pins)
total_users = len(users)
STARTING_BALANCE_CHECKING = 500
STARTING_BALANCE_Savings_1 = 1500
STARTING_BALANCE_Savings_2 = 5000
BALANCE_Checking = STARTING_BALANCE_CHECKING
BALANCE_Savings_1 = STARTING_BALANCE_Savings_1
BALANCE_Savings_2 = STARTING_BALANCE_Savings_2
DEPOSIT_TALLY_CHECKING = 0
DEPOSIT_TALLY_SAVINGS_1 = 0
DEPOSIT_TALLY_SAVINGS_2 = 0
WITHDRAWAL_TALLY_CHECKING = 0
WITHDRAWAL_TALLY_SAVINGS_1 = 0
WITHDRAWAL_TALLY_SAVINGS_2 = 0
DEPOSIT_AMOUNT = 0
#################################################################################
## User Input: Account
#### http://introtopython.org/while_input.html
#################################################################################
cls()
#print ("#####")
startup()
While_Account_Input=0
while While_Account_Input == 0:
User_Account = input("Please enter your seven digit Account Number or 0 to exit: ")
# https://snakify.org/en/lessons/if_then_else_conditions/
if User_Account == '0':
print ("You entered 0, exiting program.")
quit()
elif len(User_Account) < 7:
if User_Account == "?":
help()
else:
print ("The entered string was too short: " + str(len(User_Account)))
elif len(User_Account) > 7:
print ("The entered string was too long: " + str(len(User_Account)))
else:
print ("The entered string was correct: " + str(len(User_Account)))
#########################################################
### Length was correct, but is it a valid account?
### Check 'accounts' list to see if typed in value exists
### We really don't care if the user put in alpha
### characters, it will fail the lookup.
#########################################################
if User_Account not in accounts:
print ("Account not found")
else:
While_Account_Input=1
#####################################################
## We have some valid input -> Find the position
#####################################################
account_position = accounts.index(User_Account)
####################################################
## debug to dump out known elements to screen
####################################################
if debug == 1:
print ("Debugging Enabled")
print ("Total Accounts: " + str(total_accounts))
print ("Total Pins: " + str(total_pins))
print ("Total Users: " + str(total_users))
print ("Entered Account: " +User_Account)
print ("Account Position: " + str(account_position))
print ("Pin at Pos " + str(account_position) + ": " + pins[account_position])
print ("User at Pos " + str(account_position) + ": " + users[account_position])
cls()
####################################################
# PIN Check
####################################################
While_PIN_Input=0
PIN_Input_Fail=0
while While_PIN_Input==0:
print ("Account: " +User_Account)
User_PIN = input("Please enter your four digit PIN Number or 0 to exit: ")
# https://snakify.org/en/lessons/if_then_else_conditions/
if User_PIN == '0':
print ("You entered 0, exiting program.")
quit()
elif len(User_PIN) < 4:
if User_PIN == "?":
help()
else:
print ("The entered string was too short: " + str(len(User_PIN)))
elif len(User_PIN) > 4:
print ("The entered string was too long: " + str(len(User_PIN)))
else:
print ("The entered string was correct: " + str(len(User_PIN)))
#########################################################
### Length was correct, but is it a valid match for ?
### Check 'accounts' list to see if typed in value exists
### We really don't care if the user put in alpha
### characters, it will fail the lookup.
#########################################################
if User_PIN == pins[account_position]:
While_PIN_Input=1
else:
PIN_Input_Fail=PIN_Input_Fail+1
if PIN_Input_Fail == PIN_Max_Attempts:
cls()
print ("*****************************************************************")
print ("You have failed to enter a correct PIN. Please contact the bank.")
print ("*****************************************************************")
EXIT = input("Press ENTER to exit")
quit()
else:
print ("Incorrect PIN. Attempt "+str(PIN_Input_Fail)+" of "+str(PIN_Max_Attempts))
############################################################
## If you are here, you are logged in
############################################################
############################################################
# Two level while
## Level 1: main_menu area
#### Level 2: each individual option
############################################################
WHILE_MAIN_MENU = 0
while WHILE_MAIN_MENU == 0:
cls()
header()
main_menu()
main_menu_input = input ("Enter your choice: ")
print (main_menu_input)
if main_menu_input == '4':
print ("Selected Exit...")
WHILE_MAIN_MENU = 1
elif main_menu_input == '1':
print ("Selected Balance Inquiry...")
cls()
header()
balance_display()
EXIT = input("Press ENTER to return to Main Menu... ")
elif main_menu_input == '?':
print ("Selected Ledger Inquiry...")
cls()
header()
ledger()
EXIT = input("Press ENTER to return to Main Menu... ")
elif main_menu_input == '2':
################################### DEPOSITS START #####################################
print ("Selected Deposits...")
WHILE_DEPOSITS_MENU = 0
while WHILE_DEPOSITS_MENU == 0:
cls()
header()
########################### How much to deposit?
print ("How much would you like to deposit?")
DEPOSIT_AMOUNT = input ("[0 to return, max deposit is $1000]: ")
if DEPOSIT_AMOUNT == '0':
print ("!")
WHILE_DEPOSITS_MENU=1
elif float(DEPOSIT_AMOUNT) > 1000:
BAD_ENTRY = input ("Max entry is $1000. Press ENTER to continue")
print ("!22")
WHILE_DEPOSITS_MENU=1
else:
################################################
## **** !!!!!!!! NEED TO ADD A TALLY SYSTEM FOR DEPOSITS
## DONE !!!!!!!! NEED TO ADD A 0 <> 1000 CHECK
################################################
print (" 1. Checking")
print (" 2. Savings [1]")
print (" 3. Savings [2]")
print (" 4. Return to Menu [2]")
################################################
DEPOSIT_SELECTION = input ("Which acount would you like to make a deposit into? ")
if DEPOSIT_SELECTION == '4':
WHILE_DEPOSITS_MENU = 1
elif DEPOSIT_SELECTION == '1':
BALANCE_Checking=float(DEPOSIT_AMOUNT) + float(BALANCE_Checking)
DEPOSIT_TALLY_CHECKING = float(DEPOSIT_TALLY_CHECKING) + float(DEPOSIT_AMOUNT)
DEPOSIT_AMOUNT = 0
WHILE_DEPOSITS_MENU = 1
elif DEPOSIT_SELECTION == '2':
BALANCE_Savings_1=float(DEPOSIT_AMOUNT) + float(BALANCE_Savings_1)
DEPOSIT_TALLY_SAVINGS_1 = float(DEPOSIT_TALLY_SAVINGS_1) + float(DEPOSIT_AMOUNT)
DEPOSIT_AMOUNT = 0
WHILE_DEPOSITS_MENU = 1
elif DEPOSIT_SELECTION == '3':
BALANCE_Savings_2=float(DEPOSIT_AMOUNT) + float(BALANCE_Savings_2)
DEPOSIT_TALLY_SAVINGS_2 = float(DEPOSIT_TALLY_SAVINGS_2) + float(DEPOSIT_AMOUNT)
DEPOSIT_AMOUNT = 0
WHILE_DEPOSITS_MENU = 1
################################### DEPOSITS END #####################################
elif main_menu_input == '3':
################################### WITHDRAWALS START #####################################
print ("Selected Deposits...")
WHILE_WITHDRAWALS_MENU = 0
while WHILE_WITHDRAWALS_MENU == 0:
cls()
header()
########################### How much to withdraw? ###############################
# Withdraw amounts can only be $20, $40, $60, $80, or $100.
# Cannot withdraw more money than what exists in the account.
# Total withdraws from a single account cannot exceed $300.
# Total withdraws from ALL accounts cannot exceed $750.
#################################################################################
WITHDRAWAL_AMOUNT = 0 #Reset
##################################################################################
######### Total withdraws from ALL accounts cannot exceed $750.
######### Let's just check it as it comes into the menu, if you don't have the $,
######### don't waste time going through the tree
##################################################################################
if WITHDRAWAL_TALLY_CHECKING+WITHDRAWAL_TALLY_SAVINGS_1+WITHDRAWAL_TALLY_SAVINGS_2+20 > 750:
print ("Any more transactions will exceed your daily withdrawal limit.")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
else:
print ("------------------------------------")
print (" 1. $20 4. $80")
print (" 2. $40 5. $100")
print (" 3. $60 0. Return to Menu")
print ("------------------------------------")
WITHDRAWAL_AMOUNT_SELECTION = input ("How much would you like to withdraw? ")
if WITHDRAWAL_AMOUNT_SELECTION == '0':
print ("!")
WHILE_WITHDRAWALS_MENU=1
elif WITHDRAWAL_AMOUNT_SELECTION == '1':
WITHDRAWAL_AMOUNT = 20
elif WITHDRAWAL_AMOUNT_SELECTION == '2':
WITHDRAWAL_AMOUNT = 40
elif WITHDRAWAL_AMOUNT_SELECTION == '3':
WITHDRAWAL_AMOUNT = 60
elif WITHDRAWAL_AMOUNT_SELECTION == '4':
WITHDRAWAL_AMOUNT = 80
elif WITHDRAWAL_AMOUNT_SELECTION == '5':
WITHDRAWAL_AMOUNT = 100
else:
WHILE_WITHDRAWALS_MENU=1
if WHILE_WITHDRAWALS_MENU == 0:
######### Total withdraws from ALL accounts cannot exceed $750.
if WITHDRAWAL_TALLY_CHECKING+WITHDRAWAL_TALLY_SAVINGS_1+WITHDRAWAL_TALLY_SAVINGS_2+WITHDRAWAL_AMOUNT > 750:
print ("This transaction will exceed your daily withdrawal limit.")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
if WHILE_WITHDRAWALS_MENU == 0:
if debug == 1:
ledger()
##### WHICH ACCOUNT? ######
print ("------------------------------------")
print (" 1: CHECKING ")
print (" 2: SAVINGS[1]")
print (" 3: SAVINGS[2]")
print (" ")
print (" 0: Return to Menu")
print ("------------------------------------")
WITHDRAWAL_SELECTION = input ("Which account would you like to make a withdrawal from? ")
if WITHDRAWAL_SELECTION == '0':
print ("!")
WHILE_WITHDRAWALS_MENU=1
# Cannot withdraw more money than what exists in the account.
# Total withdraws from a single account cannot exceed $300.
elif WITHDRAWAL_SELECTION == '1':
print ("CHECKING")
if WITHDRAWAL_AMOUNT + WITHDRAWAL_TALLY_CHECKING > 300:
print ("You have exceeded your daily individual account withdrawal limit.")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
elif BALANCE_Checking - WITHDRAWAL_AMOUNT < 0:
print ("Insufficient funds..")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
else:
WITHDRAWAL_TALLY_CHECKING = WITHDRAWAL_TALLY_CHECKING+WITHDRAWAL_AMOUNT
BALANCE_Checking = BALANCE_Checking-WITHDRAWAL_AMOUNT
elif WITHDRAWAL_SELECTION == '2':
print ("SAVINGS[1]")
if WITHDRAWAL_AMOUNT + WITHDRAWAL_TALLY_SAVINGS_1 > 300:
print ("You have exceeded your daily individual account withdrawal limit.")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
elif BALANCE_Savings_1 - WITHDRAWAL_AMOUNT < 0:
print ("Insufficient funds..")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
else:
WITHDRAWAL_TALLY_SAVINGS_1 = WITHDRAWAL_TALLY_SAVINGS_1+WITHDRAWAL_AMOUNT
BALANCE_Savings_1 = BALANCE_Savings_1-WITHDRAWAL_AMOUNT
elif WITHDRAWAL_SELECTION == '3':
print ("SAVINGS[1]")
if WITHDRAWAL_AMOUNT + WITHDRAWAL_TALLY_SAVINGS_2 > 300:
print ("You have exceeded your daily individual account withdrawal limit.")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
elif BALANCE_Savings_2 - WITHDRAWAL_AMOUNT < 0:
print ("Insufficient funds..")
EXIT = input("Press ENTER to return to Main Menu... ")
WHILE_WITHDRAWALS_MENU=1
else:
WITHDRAWAL_TALLY_SAVINGS_2 = WITHDRAWAL_TALLY_SAVINGS_2+WITHDRAWAL_AMOUNT
BALANCE_Savings_2 = BALANCE_Savings_2-WITHDRAWAL_AMOUNT
else:
WHILE_WITHDRAWALS_MENU=1
#### If you're here, you exited the main_menu
ledger()
print ("Thank you and have a good day.")