CODEWITHSUNDEEP
python
ATMathew
ATMathew

Reputation: 12856

Adding values to a list

I'm an R newbie and am trying to create a basic "database" for my comic books. However, I have a problem.

The idea is to place each new entry as a list. I assumed that I could set up the lists to look like the following.

[Thor, 50, Marvel]
[Thor, 51, Marvel]
[Thor, 52, Marvel]
...
eventually, I 'd like to include entries for story arc, writer, artist, etc.

However, I'm using the following code to enter in the comics and have found that each new entry is just added to the end of the list.

option = 0
comicdb = []

while option != 3:
    print "--------------------------"
    print "1. Add a New Comic Book"
    print "2. Print the Database"
    print "3. Quit"
    option = int(raw_input("Pick an Option: "))
    if option == 1:
        title = raw_input("Comic Book Title: ")
        issue = int(raw_input("Issue Number: "))
        publisher = raw_input("Publisher: ")
        comicdb.append(title)
        comicdb.append(issue)
        comicdb.append(publisher)
        print comicdb

After running the code a couple times, the list looks like:

['Thor', 50, 'Marvel', 'Thor', 51, 'Marvel', 'Thor', 52, 'Marvel']

I'm assuming that one of the following things is wrong, but I can't figure it out:

  1. append is the wrong command to use
  2. i should use a dictionary or tuple instead of a list

Help!

Upvotes: 3

Views: 20473

Answers (4)

Escualo
Escualo

Reputation: 42072

As much as I commend your effort in writing a database from scratch, I must recommend that you have a look at SQLAlchemy - a Python "object relational mapper" that allows you to connect Python objects to SLQ-like databases (chiefly SQLite, the simplest, server-free one). I am amazed by the complexity that can be attained with very little code. It is clean, powerful, easy to understand, and grows rapidly.

I use it at work very successfully, and at home to keep track of all my daughters pictures (I have more megabytes (teras?) of picture of my daughters at home than I have from Cassini spacecraft at work, mind you).

So, if you are just practicing - go ahead. If you want to stand on solid ground and have a great and neat application for keeping track of your comics, then have a look at any database manager, but I recommend Python / SQLAlchemy.

Cheers.

Upvotes: 0

lamwaiman1988
lamwaiman1988

Reputation: 3742

The answer is simple. you insert 3 words to the list instead of appending a list which contains the 3 words.

It should be like this:

option = 0
comicdb = []

while option != 3:
    print "--------------------------"
    print "1. Add a New Comic Book"
    print "2. Print the Database"
    print "3. Quit"
    option = int(raw_input("Pick an Option: "))
    if option == 1:
        title = raw_input("Comic Book Title: ")
        issue = int(raw_input("Issue Number: "))
        publisher = raw_input("Publisher: ")
        temp_list = []
        temp_list.append(title)
        temp_list.append(issue)
        temp_list.append(publisher)
        comicdb.append(temp_list)
        print comicdb

Upvotes: 4

eat_a_lemon
eat_a_lemon

Reputation: 3208

You need a list of lists or a list of dictionaries.

record = {}
record['title'] = raw_input("Comic Book Title: ")
record['issue'] = int(raw_input("Issue Number: "))
record['publisher'] = raw_input("Publisher: ")
comicdb.append(record)
print comicdb

Upvotes: 1

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 798456

You should use a nested structure.

comicdb.append((title, issue, publisher))

Upvotes: 4

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