Orion514 / CFG-Generator

Python Control Flow Graph Generator

Python Control Flow Graph Generator

A project to generate control flow graph for Python, written in Python3. The file cfg_orig.py is derived from staticfg and is for comparison. cfg_orig.py has the exact same function as staticfg. cfg.py added support for

• exception handling

• lambda expression

• generator expression

• list/set/dict comprehension

• for-else/while-else

• ...

It also fixed some minor bugs in the original code.

Dependencies

• Python3

• autopep8

• graphviz

• astor

Usage

python3 cfg.py code.py

Demo

Try-Except-Else-Finally

try:
    b = b + 5
except KeyError:
    a += 1
except ZeroDivisionError:
    a += 2
else:
    a += 3
finally:
    b += 1
    a = a - b
    print('finish')

Lambda Expression

a = lambda x: 2 * x + 5 if x > 10 else 10 if x == 10 else 3 * x

List Comprehension

a = [2 * x for x in y if x > 0 for y in z if y[0] < 3]

For-Else Statement

digits = [0, 1, 5]

for i in digits:
    a += i
    if i == 5:
        print("5 in list")
        break
else:
    print("out of the loop")

a += 1
b += 2