Redo #313 on the correct branch.
Declare success_indicator as a local variable, not a GLOBAL CONSTANT.
* By convention, values that may change at runtime should not be in UPPERCASE.
* A global variable can be read from either with or without a global statement
* A global variable can be written to only when preceded by a global statement
```python
>>> SUCCESS_INDICATOR = 0
>>> def read_from_global():
... print(SUCCESS_INDICATOR)
...
>>> def write_to_declared__global():
... global SUCCESS_INDICATOR
... SUCCESS_INDICATOR += 1
...
>>> def write_to_undeclared__global():
... SUCCESS_INDICATOR += 1
...
>>> read_from_global()
0
>>> write_to_declared__global()
>>> read_from_global()
1
>>> write_to_undeclared__global()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 2, in write_to_undeclared__global
UnboundLocalError: local variable 'SUCCESS_INDICATOR' referenced before assignment
```
Chris Clauss
Chris Simpkins