Jost review suggestions

Author: Robadob

episodes/files/pred-prey/predprey.py

@@ -1,3 +1,4 @@
+import sys
 import math
 import numpy as np
 import matplotlib.pyplot as plt

episodes/profiling-lines.md

@@ -466,11 +466,6 @@ from line_profiler import profile
 Since this will take much longer to run due to `line_profiler`, you may wish to profile fewer `steps` than you did in the function-level profiling exercise (250 was suggested for a full run).
 In this instance it may change the profiling output slightly, as the number of `Prey` and their member variables evaluated by this method both change as the model progresses, but the overall pattern is likely to remain similar.
 
-```python
-# line ~420
-model = Model(50) # 50 steps (originally defaulted to 250)
-```
-
 Alternatively, you can kill the profiling process (e.g. `ctrl + c`) after a minute and the currently collected partial profiling information will be output.
 
 This will produce output similar to that below.