Implicit enumerate calls found PTC-W0060
Using range(len(...)) is not pythonic. Python does not have not index-based loops. Instead, it uses collection iterators. Python has a built-in method enumerate which adds a counter to an iterable.
Function is too complex FLK-C901
Too many decision blocks were found, which is why the code has been tagged as complex. You should consider refactoring the code for simplicity. Read more about cyclomatic complexity here.
Pythagorean calculation detected with sub-optimal numerics PTC-W0028
Calculating the length of the hypotenuse using the standard formula c = sqrt(a**2 + b**2) may lead to overflow if the two other sides are both very large. Even though c will not be much bigger than max(a, b), either a**2 or b**2 (or both) could be. Thus, the calculation could overflow, even though the result is well within representable range. It is recommended to use the built-in function hypot(a,b) from the math library.
Simplify boolean expression PYL-R1709
The boolean expression with redundant pre-python 2.5 ternary syntax is used and can be simplified for better readability. Please look at the issue text for suggestion.
Unnecessary delete statement in a local scope PTC-W0043
Passing a local variable to a del statement results in that variable being removed from the local namespace. When exiting a function all local variables are deleted, so it is unnecessary to explicitly delete variables in such cases.