Externally scoped variables in IronPython delegates - delegates

Question

In IronPython, I can't seem to get a variable from outside a delegate's scope to change (or even appear) inside its scope. This is contrary to what I can do in both C# and Python.
In C#, I could do the following (contrived) example:
public delegate bool Del(int index);
public static void Main() {
int itemTally = 0;
Del d = delegate (int index) {
itemTally += 3;
return true;
};
for (int i = 4; i < 6; i++) {
d.Invoke(i);
}
Console.WriteLine(itemTally); // prints 6
}
I can do the same thing in Python:
item_tally = 0
def delegate(index):
global item_tally
item_tally += 3
for x in range(4, 6):
delegate(x)
print(item_tally) # prints 6
but changing a Python variable in a Python delegate called by C# will crash:
public class BatchProcessor {
public delegate bool Del(int index);
public static int ProcessBatches(Del the_delegate) {
int batchTally = 0;
for (int i = 4; i < 6; i++) {
the_delegate(i);
batchTally++;
}
return batchTally;
}
}
import BatchProcessor
item_tally = 0
def delegate(index):
global item_tally
item_tally += 3 # "global name 'total_count' is not defined"
return True
batch_tally = BatchProcessor.ProcessBatches(BatchProcessor.Del(delegate))
print(item_tally)
Is there a way to increment total_count in the Python delegate without changing any C#?

Answer 1

Adding an extra global line to the IronPython in the scope outside the delegate got it working. That line wasn't necessary in the Python-only version:
public class BatchProcessor {
public delegate bool Del(int index);
public static int ProcessBatches(Del the_delegate) {
int batchTally = 0;
for (int i = 4; i < 6; i++) {
the_delegate(i);
batchTally++;
}
return batchTally;
}
}
import BatchProcessor
global item_tally # Adding this line made it work.
item_tally = 0
def delegate(index):
global item_tally # You need to keep this line, too.
item_tally += 3
return True
batch_tally = BatchProcessor.ProcessBatches(BatchProcessor.Del(delegate))
print(item_tally) # prints 6