StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
primarykey
Id
16728259
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2013-05-24T05:33:52.130
FavoriteCount
0
LastActivityDate
2013-05-24T05:33:52.130
LastEditDate
LastEditorUserId
0
OwnerUserId
1968182
ParentId
16727319
PostTypeId
2
Score
0
ViewCount
0
LastEditorDisplayName
text
Body
Firstly, the approach looks pretty good for a beginner, thumbs up! Now, to answer your question from the title, the error comes from accessing an element of a sequence that doesn't exist, like e.g. the fifth element of a sequence of four elements. In your case, I guess this is triggered by the <code>cformula[index + 1]</code>, where the index could already be that of the last element. Note that it would also be interesting to know which input triggered this error, my guess is "CO" or "C2H5OH", because both have a compound letter not followed by a numer at the end. Now, how to get around it? A very simple approach is to simply take the rest of the string (which can be empty) and handle its content. <pre><code>count = '' for d in cformula[index + 1:]: if d.isdigit(): count += d else: break </code></pre> This code store all digits after <code>cformula[index]</code> up to the next non-digit. If there are no digits, it store an empty string. Note that this doesn't even care which atom (C, H, O) you are looking at, so it is a good example for code that you could move to a separate function. Then, after calling that function, you check the string of digits: <pre><code>if count == '': # number of atoms is implicitly 1 atoms = 1 else: # number of atoms is explicitly given atoms = int(count) # TODO: discard len(count) elements from the input string </code></pre> BTW: There is a <code>dict</code> type which you could use to store the number of atoms for each element. Similarly, you could use it to store the weight of each atom type: <pre><code>atom_weight = {'C': 15.994, 'H': 1.0079, 'O': 12.011,} weight = atom_weight['C'] * C1 + atom_weight['H'] * H1 + atom_weight['O'] * O1 </code></pre> This doesn't make your code correct, but makes it easier to extend that to the rest of the periodic table. :)
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POIndex Error: List Index out of range
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USUlrich Eckhardt
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. This table or related slice is empty.
VotesPostIdCreationDate
1. This table or related slice is empty.
CommentsPostId
1. This table or related slice is empty.

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.