捕捉异常并进行格式化输出

traceback.py

import sys
import inspect
import textwrap

def error():
    raise ZeroDivisionError

try:
    error()
except:
    etype, evalue, etb = sys.exc_info()
    info = inspect.getframeinfo(etb.tb_next, context=3)
    lines = info.code_context
    firstlineno = info.lineno - info.index
    fmt = '<{}'.format(len(str(firstlineno+ len(lines))))
    msg = '>!  {etype} at {filename}:{lineno}'.format(fmt=fmt,
        etype=etype, filename=info.filename, lineno=info.lineno)
    print(msg)
    lines = textwrap.dedent(''.join(lines))
    for i, line in enumerate(lines.split('\n')):
        msg = '{lineno:{fmt}}{seq}\t{line}'.format(
            fmt=fmt, lineno=firstlineno+i,
            seq=('>' if i==info.index else ':'), line=line)
        print(msg)