.keyfor a variable that doesn't exist
), or a closing
5after the file location, which tells us where the exact line with the code that resulted in the error. The stack traceback shows the functions that were called that led up to that.
ais called at line 12, then function
bis called at line 9 inside of
cis called at line 7 inside of function
b, and finally at line 5, the error occurs inside of function