Display a traceback with variables in the statement where the error occurred

traceback_with_values.py

# coding: utf-8


r"""
Sample output:

    C:\Users\USERNAME\repos\python3-exception-with-values>python traceback_with_values.py
    Traceback (most recent call last):
    File "traceback_with_values.py", line 45, in <module>
        print(float(x) + y)
    ValueError: could not convert string to float: 'hoge'
    Values in the statement:
      y=fuga
      x=hoge
"""


import sys
import ast
import traceback
import contextlib


def print_exception_with_values(etype, evalue, tb):
    traceback.print_exception(etype, evalue, tb)

    source = None
    lines = ''.join(traceback.format_exception(etype, evalue, tb)[:-1]).splitlines()
    for i, line in enumerate(lines):
        line = line.strip()
        if line.startswith('File'):
            if i+1 < len(lines) and lines[i+1].startswith('    '):
                source = lines[i+1].strip()

    if source is None:
        sys.stderr.write('source code is not found in traceback.\n')
        return

    tree = ast.parse(source)

    sys.stderr.write('Values in the statement:\n')
    for node in ast.walk(tree):
        if isinstance(node, ast.Name):
            if isinstance(node.ctx, ast.Load):
                if node.id in tb.tb_frame.f_locals:
                    sys.stderr.write('  {}={}\n'.format(node.id, tb.tb_frame.f_locals[node.id]))
                elif node.id in tb.tb_frame.f_globals:
                    sys.stderr.write('  {}={}\n'.format(node.id, tb.tb_frame.f_globals[node.id]))


sys.excepthook = print_exception_with_values


x = 'hoge'
y = 'fuga'
print(float(x) + y)

Hi, ran into this git googling alternatives for my package. Have a look at this
https://github.com/andy-landy/traceback_with_variables/blob/master/traceback_with_variables/core.py#L19
I guess it does pretty much the same but note that there a standard tools to access all variables without parsing the code tree. I think one can boil the code I mentioned down to a rather small one by eliminating parameters.