Python: Nested List Inside Dictionary?

Question

I'm currently stuck with this output of a nested list when trying to append the list as the definition of my dictionary.

I know this is probably more code than I should include, but I figured it's helpful to show more than less.

class Account:

    accountInfo = {} #ex. ID : 5FE19C (hexadecimal ID's)

    def __init__(self):
        choice = raw_input("Would you like to login or signup?\n")
        if choice.lower() == "login":
            self.login()

        elif choice.lower() == "signup":
            print "Great! Fill in the following."
            self.signup()

        else:
            self.__init__()

    def signup(self):
        import random

        accountID = '%010x' % random.randrange(16**10) # 10 digit hexadecimal ID generator
        personalInfo = []

        self.accountInfo[accountID] = []

        firstName = raw_input("First Name: ")
        lastName = raw_input("Last Name: ")
        email = raw_input("E-Mail: ")
        password = raw_input("Password: ")
        birthdate = raw_input("DOB (DD/MM/YYYY): ")
        alias = raw_input("Username/Alias: ")

        personalInfo.append(firstName)
        personalInfo.append(lastName)
        personalInfo.append(email)
        personalInfo.append(password)
        personalInfo.append(birthdate)
        personalInfo.append(alias)

        for i in range(1):
            self.accountInfo[accountID].append(personalInfo)
            #creates an unwanted nested list, but the output is correct

        print self.accountInfo

I don't understand why I'm getting the output of a nested list in my dictionary. The contents of the dictionary are correct, but it's just that unwanted and unnecessary nested list.

output:

>>> {'6de7bcf201': [['firstName', 'lastName', 'email', 'password', 'birthdate', 'alias']]}

Answer 1

personalInfo = []  # PersonalInfo is a list
# skipped
self.accountInfo[accountID].append(personalInfo)  # add list to the list

This is similar to

main = []
p_info = []
main.append(p_info)  # result would be main = [[]]

If you want to have just a dict inside list, change personalInfo to {} that would requare to change personalInfo.append to personalInfo[x] = y

Answer 2

personalInfo is a list and self.accountInfo[accountID] is another list.

With self.accountInfo[accountID].append(personalInfo) you are injecting one inside the other.

You can do self.accountInfo[accountID] = personalInfo

And what's the point of for i in range(1) ? It's not looping at all!

Answer 3

I think this is pretty straight forward:

personalInfo is a list. You append items to it and get something like [..,..,..] . You initiate the value of self.accountInfo[accountID] also as a list. Then you append your first list to the second list, giving you a list of lists.

Instead of self.accountInfo[accountID].append(personalInfo) try self.accountInfo[accountID] = personalInfo

Answer 4

Welcome! A couple of things:

Imports should generally be at the top of a file. For your signup function, the import random should be at the top.

Your __init__ shouldn't be called again on a class. __init__ is considered the "constructor" of the class - as such it should generally be called once. Consider putting your raw_input section in another function and call that twice.

Print is a function, not a statement (your last line)

To answer your question, you have a nested list because you are making two lists. You're first building up personalInfo and then appending that item to the empty list you made for accountInfo you can have a single-level list if you just set self.accountInfo[accountID] = personalInfo`.

Answer 5

I can't test right now but:. Replace self.accountInfo[accountID] = [] with self.accountInfo[accountID] = personalInfo . And delete for i in range(1): self.accountInfo[accountID].append(personalInfo)