I have the following code which prompts the user for a username, then checks if that username exists in a json file, if so the script should prompt the user 3 times maximum to enter another username, otherwise just accept the entered username and continue.
The issue comes when I try to reinitiate the for loop j = test1["users"][0] so that in the second attempt, this script checks the json file from the beginning not from the point it was.
When the script comes back to the for loop after the else statement, it just simply ignores the whole loop and continue to the next section of the code without any error...
The for loop is looping in a dictionary which is in a list:
#prompt for username
x["User Name"] = input("Please type your user name: ")
i = 0
#for loop to check if the entered username already exists
for j in test1["users"]:
while j["User Name"] != x["User Name"] and i < 3:
break
else:
print("username already exists, try again")
x["User Name"] = input("Please type a new user name: ")
i += 1
j = test1["users"][0]
#prompts the user for additional information if username pass `succesfully`
x["First Name"] = input("Please type your first name: ")
x["Last Name"] = input("Please type your last name: ")
x["Age"] = input("Please type your age: ")
A sample of test1["users]:
{
"users": [
{
"First Name": "jhon",
"Age:": "30",
"Last Name": "kerry",
"User Name": "jhon",
"Height": "170",
"Weight": "70"
},
For this case you dont want to use break but continue .
Here is a good tutorial where you can find more detailed explainations: https://docs.python.org/3/tutorial/controlflow.html?highlight=break
Guys thanks for your support, just wanted to say I solved the issue. Basically the challenge was:
I have a list of users in a json format or in a dictionary, in the end it doesn't matter.
I prompt the user to enter basic information and then I will append the information to the json file if the user name doesn't already exists there.
If the username already exists, the user has 3 additional attempts to enter another username.
The script must check again in the whole file if the new typed user exists or not in order to continue.
The issue was in the last point, because I needed to loop again in a for statement that could be in the middle of its job, which could result in duplicated records if the username existed in previous records.
My first attempt was to try to restart the for loop with this statement j = test1["users"][0] so that the loop started over, but that one didn't work. In the end the solution I came up with is using an additional loop that forces the for loop to be restarted. If you play with a while and a boolean variable the issue will get solved!! :)
That's the final code:
x["User Name"] = input("Please type your user name: ")
#initializing variables that restart for loop and restrict username input to 3
i = True
n = 0
#additional while loop to restart for loop
while i and n <= 3:
i = False
if n == 3:
print("Thank you")
exit()
#looping a list in a diciontary
for j in test1["users"]:
while j["User Name"] != x["User Name"]:
break
#telling the user the username already exists and prompting for new username
else:
print("existing user")
x["User Name"] = input("Type new user name")
n += 1
i = True
break
x["First Name"] = input("Please type your first name: ")
x["Last Name"] = input("Please type your last name: ")
Thanks everyone!!
Related
I am super new to programming so sorry if this is a common question. I am trying to alter elements such as first name/last name etc in a 2d list whereby a user inputs a username, if the username returns true then the user is asked to select an option of what they would like to change first name or last name. My code only changes the first name or last name of the first list within the 2d list. Does anyone know how to specifically target a list element based on a users selection of an element within that list? any help would be greatly appreciated :).
allUserDetails = [["John", "Doe", "User", "Sales", "johndoe91", "password"],
["James", "Hill", "Admin", "Administrator", "hill95", "12345678"]]
def update_user():
print("\n:: Update User ::")
print("-" * 25)
print("\nWhich field would you like to update?\n")
print("1. First Name")
print("2. Last Name")
print(allUserDetails)
searchUser = input("\nInput username to edit (press 1 to return to Main Menu): ").lower()
while searchUser != "1":
for x in allUserDetails:
if x[4] == searchUser:
print()
print(searchUser, "found in the list")
update_user()
updateSelection = input("\nInput number of field or press Q/q to return to Menu 3: ")
if updateSelection == "1":
newFirstName = input("Input new First Name: ")
allUserDetails[0][0] = newFirstName
print(allUserDetails)
if updateSelection == "2":
newLastName = input("Input new Last Name: ")
allUserDetails[0][1] = newLastName
print(allUserDetails)
if updateSelection == ("Q", "q"):
searchUser = input("\nInput username to edit (press 1 to return to Main Menu): ").lower()
for x in allUserDetails:
if x[4] != searchUser:
# Print not found message
print()
print(searchUser, "not found")
continue
else:
break
Your issue comes from the indexing of the list:
allUserDetails[0][0] = newFirstName
This will always update the first index. However, you are trying to update list x:
x[0] = newFirstName
The same issue applies to the newLastName
I'm trying to get my code to check if a word is already in the document. However when choosing a variable (username) that happens to share the same letters going to the right as the preexisting one in the file, it thinks that the name is taken. For example, if abcdefg was in the file, if I was to right defg or fg or g, it would think the username was taken.
def register():
print("━━━━ACCOUNT CREATION━━━━")
username = input("Create Username: ")
with open("Login.txt", "r") as loginfile:
if (username+",") in loginfile.read():
print("Sorry, but that username is taken.")
choice = input("Try again with a new name? (Y/N)")
choice = choice.upper()
My case:
Say I had the name, Joe which is already in the file. If I tried to make a username that is just e, then it would think it is Joe, as it is looking for the e, next to a comma.
Anyway to fix this? Thanks!
This should work
with open('login.txt', 'r') as LoginFile:
# the split function splits a string to a list on mark
Data = LoginFile.read().split(" ,")
if username in Data:
# .....
if this isn't what you want try this built-in module :
https://docs.python.org/3/library/re.html
def register():
print("━━━━ACCOUNT CREATION━━━━")
# read the names from the file
with open('Login.txt', 'r') as f:
names = f.read().split(',')
username = input("Create Username: ")
for name in names:
# check if any names end with this name have been created
if name.endswith(username):
# found
print("Sorry, but that username is taken.")
# we want to keep ask the user to select if
# they enter something other than Y/N
while True:
# ask for the option
option = input("Try again with a new name? (Y/N) ")
# try again, we just rerun this function
if option == 'Y':
register()
# don't ask any more
break
elif option == 'N':
# exit if user chooses N
break
# if the user chooses something else, continue
# the loop and keep asking
# if no names end with username, goto else
break
else:
# name available, save it to the file
print("Name created successfully:", username)
new_names = names + [username]
with open('Login.txt', 'w') as f:
f.write(','.join(new_names))
I have tested it, please try and see if it works for you.
im on the first part of my course work and im cleaning it up
i want to keep copying and pasting but i know looping it is time efficient and infinite
username = ["bob", "kye", "mes", "omar", "luke", "ben", "robin", "sam"]
name=str(input("whats name 1 "))
round=0
if name in username:
print(" p1 Authenticated")
name2=str(input("whats name 2 "))
if name2 in username:
print(" *STARTING GAME* ")
else:
print("Invalid User")
else:
print("Invalid User")
if you type and name not previously made it should loop like try again till a valid name is typed up
but if i type something wrong code continues and stops when they needs the name
This piece of code would ask for the name as many times needed until the user inserts the valid name.
name_one = ''
name_two = ''
usernames = ['bob', 'kye', 'mes', 'omar']
while name_one not in usernames:
name_one = input('Insert first name: ')
while name_two not in usernames:
name_two = input('Insert first name: ')
Another way would be:
names = []
usernames = ['bob', 'kye', 'mes', 'omar']
while len(names) < 2:
name = input('Insert name: ')
if name in usernames:
names.append(name)
else:
print('Invalid user, try again')
The second example you make a loop that is aways verifying if the list of names has at least two names if it does the loops breaks and the code continues. Then to access each name you use names[0] and names[1].
As commented by Patrick, you should try reading about loops.
I am trying to finish off my program my adding a menu that allows the user to select a few options that allow the user to store website names and passwords in lists. But there was a problem as soon as I have appended some website names and passwords into their respective vaults where whenn I try to select an option after appending the website names and passwords, "1" for example is the expected input to call the viewapp() function to see the websites and passwords stored so far. The thing is it takes more than twice to call the viewapp() function, where it rejects the first expected input but accepts the 2nd one strangely. Also when I select the 3rd option for the purpose to call summary(), the whole printed summary would print out twice, which is a similar pattern to the menu only accepting the 2nd expected input. The program is doing what I want except for this annoying bug where selecting those four options makes it ask for input a second time when it's supposed to straight away jump to that function. Help would be appreciated.
appvault = []
passvault = []
def logged():
print("----------------------------------------------------------------------\n")
print("Hello, welcome to the password vault console. ")
modea = input("""Below are the options you can choose from in the password vault console:
##########################################################################\n
1) Find the password for an existing webiste/app
2) Add a new website/app and a new password for it
3) Summary of the password vault
4) Exit
##########################################################################\n
> """).strip()
return modea
def viewapp():
if len(appvault) > 0:
for app in appvault:
print("Here is the website/app you have stored:")
print("- {}\n".format(app))
if len(passvault) > 0 :
for code in passvault:
print("Here is the password you have stored for the website/app: ")
print("- {}\n".format(code))
else:
print("You have no apps or passwords entered yet!")
def addapp():
while True:
validapp = True
while validapp:
new_app = input("Enter the new website/app name: ").strip().lower()
if len(new_app) > 20:
print("Please enter a new website/app name no more than 20 characters: ")
elif len(new_app) < 1:
print("Please enter a valid new website/app name: ")
else:
validapp = False
appvault.append(new_app)
validnewpass = True
while validnewpass:
new_pass = input("Enter a new password to be stored in the passsword vault: ")
if not new_pass.isalnum():
print("Your password for the website/app cannot be null, contain spaces or contain symbols \n")
elif len(new_pass) < 8:
print("Your new password must be at least 8 characters long: ")
elif len(new_pass) > 20:
print("Your new password cannot be over 20 characters long: ")
else:
validnewpass = False
passvault.append(new_pass)
validquit = True
while validquit:
quit = input("\nEnter 'end' to exit or any key to continue to add more website/app names and passwords for them: \n> ")
if quit in ["end", "End", "END"]:
logged()
else:
validquit = False
addapp()
return addapp
def summary():
if len(passvault) > 0:
for passw in passvault:
print("----------------------------------------------------------------------")
print("Here is a summary of the passwords stored in the password vault:\n")
print("The number of passwords stored:", len(passvault))
print("Passwords with the longest characters: ", max(new_pass for (new_pass) in passvault))
print("Passwords with the shortest charactrs: ", min(new_pass for (new_pass) in passvault))
print("----------------------------------------------------------------------")
else:
print("You have no passwords entered yet!")
while True:
chosen_option = logged()
print(chosen_option)
if chosen_option == "1":
viewapp()
elif chosen_option == "2":
addapp()
elif chosen_option == "3":
summary()
elif chosen_option == "4":
break
else:
print("That was not a valid option, please try again: ")
print("Goodbye")
This happens because you call logged() when exiting addapp():
if quit in ["end", "End", "END"]:
logged()
Then, the choice you enter is returned by logged(), and thrown away as it isn't assigned to anything.
You're now back at the end of the previous block in addapp(), and the next instruction is return addapp, that will bring you back to your main loop, where you'll be sent to logged() again by chosen_option = logged()
Note that in return addapp, you return the addapp function itself, which is certainly not what you want to do. So, as you don't need a return value for addapp(), just use return, or nothing at all, Python will automatically return at the end of the function.
So, to solve your problem: directly return when you're done entering sites:
if quit in ["end", "End", "END"]:
return
Note also that you recursively call addapp() from itself when you add more sites.
You should generaly avoid that unless you really want to use some recursive algorithm, and rather use a loop as you did in your main loop. By default, Python limits you to 1000 recursion levels - so you could even crash your app by entering more than 1000 sites in a row ;)
The summary problem is only caused by the unnecessary for loop in summary()
You are nearly there. The issue is in the addapp() function at line 63:
if quit not in ["end", "End", "END"]:
logged()
if you replace
logged()
with
pass
Then everything will work a ok.
You are not handling the result of the logged function here anyway.
You also do not need to process the logged function here. The addapp will exit and the logged function will be called and handled in the while loop the addapp function was called from.
I am extremely new to Python, and to programming in general, so I decided to write some basic code to help me learn the ins and outs of it. I decided to try making a database editor, and have developed the following code:
name = []
rank = []
age = []
cmd = input("Please enter a command: ")
def recall(item): #Prints all of the information for an individual when given his/her name
if item in name:
index = name.index(item) #Finds the position of the given name
print(name[index] + ", " + rank[index] + ", " + age[index]) #prints the element of every list with the position of the name used as input
else:
print("Invalid input. Please enter a valid input.")
def operation(cmd):
while cmd != "end":
if cmd == "recall":
print(name)
item = input("Please enter an input: ")
recall(item)
elif cmd == "add":
new_name = input("Please enter a new name: ")
name.append(new_name)
new_rank = input("Please enter a new rank: ")
rank.append(new_rank)
new_age = input("Please input new age: ")
age.append(new_age)
recall(new_name)
else:
print("Please input a valid command.")
else:
input("Press enter to quit.")
operation(cmd)
I want to be able to call operation(cmd), and from it be able to call as many functions/perform as many actions as I want. Unfortunately, it just infinitely prints one of the outcomes instead of letting me put in multiple commands.
How can I change this function so that I can call operation(cmd) once, and call the other functions repeatedly? Or is there a better way to go about doing this? Please keep in mind I am a beginner and just trying to learn, not a developer.
Take a look at your code:
while cmd != "end":
if cmd == "recall":
If you call operation with anything than "end", "recall" or "add", the condition within while is True, the next if is also True, but the subsequent ifs are false. Therefore, the function executes the following block
else:
print("Please input a valid command.")
and the while loop continues to its next lap. Since cmd hasn't changed, the same process continues over and over again.
You have not put anything in your code to show where operator_1, operator_2, and operator_3 come from, though you have hinted that operator_3 comes from the commandline.
You need to have some code to get the next value for "operator_3". This might be from a list of parameters to function_3, in which case you would get:
def function_3(operator_3):
for loopvariable in operator_3:
if loopvariable == some_value_1:
#(and so forth, then:)
function_3(["this","that","something","something else"])
Or, you might get it from input (by default, the keyboard):
def function_3():
read_from_keyboard=raw_input("First command:")
while (read_from_keyboard != "end"):
if read_from_keyboard == some_value_1:
#(and so forth, then at the end of your while loop, read the next line)
read_from_keyboard = raw_input("Next command:")
The problem is you only check operator_3 once in function_3, the second time you ask the user for an operator, you don't store its value, which is why its only running with one condition.
def function_3(operator_3):
while operator_3 != "end":
if operator_3 == some_value_1
function_1(operator_1)
elif operator_3 == some_value_2
function_2
else:
print("Enter valid operator.") # Here, the value of the input is lost
The logic you are trying to implement is the following:
Ask the user for some input.
Call function_3 with this input.
If the input is not end, run either function_1 or function_2.
Start again from step 1
However, you are missing #4 above, where you are trying to restart the loop again.
To fix this, make sure you store the value entered by the user when you prompt them for an operator. To do that, use the input function if you are using Python3, or raw_input if you are using Python2. These functions prompt the user for some input and then return that input to your program:
def function_3(operator_3):
while operator_3 != 'end':
if operator_3 == some_value_1:
function_1(operator_3)
elif operator_3 == some_value_2:
function_2(operator_3)
else:
operator_3 = input('Enter valid operator: ')
operator_3 = input('Enter operator or "end" to quit: ')
looks like you are trying to get input from the user, but you never implemented it in function_3...
def function_3(from_user):
while (from_user != "end"):
from_user = raw_input("enter a command: ")
if from_user == some_value_1:
# etc...