nodupe | No Duplicate | Hashing library

Override the default Equals() and GetHashCode() implementations (like the others have mentioned in the comments) for the HashSet<> or Distinct() to work. You can also implement IEquatable<>, which will require you to override the Equals() and GetHashCode() methods.

You can use a generator for this.

You are refreshing rows inside the foreach, but rows is the iterable object of the foreach. That I guess isn't illegal (after all, it compiled) but seems asking for trouble. My opinion is the stale element reference is somehow related to rows being reassigned within its own foreach loop.

However, after you assign rows the 2nd time, you never use it inside the foreach. It almost seems like it is an unintentional statement that you can delete. After all, why bother assigning rows inside the foreach and then never use it inside the foreach?

If you are assigning rows a 2nd time because you are comparing to what's already been processed, I would give the 2nd rows assignment a different variable name (say, rows_B). But as I said, I don't see it happening here. You just assign rows inside foreach and never use it.

Or, if the reason for the 2nd rows assignment because the table is dynamically changing while you're processing the table? If so, I think the best you can do is catch the error and try to recover from whatever changed on you midstream. I know that sounds vague, but really, if your input data is changing while you're trying to process that input the best you could ever hope for is a best-effort effort.

For example, you could create a 2nd rows variable (say, rows_b) to refresh within the foreach loop. Then compare rows_b with the original rows. If they are identical - awesome, just keep processing.

If they differ, I would keep track of which rows you've processed to that point, break out of the loop and start over. During the foreach you'd check if a row had been previously processed and if so skip to the next iteraton.

If this is what you're trying to do - and want to see a code example - let me know. I didn't want to write the code if it isn't even what you're trying to accomplish ;-)

Your function is using return values, but you're trying to use it as it if the return values were printed. The correct usage for "if the exit status is non-zero" simplifies to

Courtesy of my colleague...

Please find a simpler approach that solves the problem

Default separator in read_csv is ,, so for tab is necessary add sep='\t' and also for inplace operation is returned None, so possible 2 solutions are remove it or not assign back:

What appears to be happening is:

• In PracticesViewController you set the model's delegate to self, as in pModel.delegate = self.
• You navigate back to your first view controller. This means that PracticesViewController gets deallocated. But the model's delegate has not been changed, so it's still pointing to the memory location where the view controller used to be.
• Later (but soon), your model tries to call a method on its delegate, but it can't because it was deallocated. This crashes your app.

You could reassign the value of the delegate, for example in viewDidAppear. Or you could have your model check whether its delegate implements a method before attempting to call it. That's a standard practice for optional protocol methods-- since they don't have to be implemented, you check first before calling them.

In general, don't use ! in Swift unless you want your code to crash there if something goes wrong.