Python当我捕获异常时,如何获取类型,文件和行号?

时间:2009-08-14 16:02:15

标签: python exception exception-handling stack-trace

捕获会打印的异常:

Traceback (most recent call last):
  File "c:/tmp.py", line 1, in <module>
    4 / 0
ZeroDivisionError: integer division or modulo by zero

我想将其格式化为:

ZeroDivisonError, tmp.py, 1

6 个答案:

答案 0 :(得分:306)

import sys, os

try:
    raise NotImplementedError("No error")
except Exception as e:
    exc_type, exc_obj, exc_tb = sys.exc_info()
    fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
    print(exc_type, fname, exc_tb.tb_lineno)

答案 1 :(得分:53)

最简单的形式对我有用。

import traceback

try:
    print(4/0)
except ZeroDivisionError:
    print(traceback.format_exc())

输出

Traceback (most recent call last):
  File "/path/to/file.py", line 51, in <module>
    print(4/0)
ZeroDivisionError: division by zero

Process finished with exit code 0

答案 2 :(得分:43)

Sourcetraceback.format_exception()(Py v2.7.3)和被叫/相关函数有很大帮助。令人尴尬的是,我总是忘记Read the Source。在我徒劳地搜索类似的细节之后,我才这样做了。一个简单的问题,“如何为异常重新创建与Python相同的输出,具有所有相同的细节?”无论他们想要什么,这都可以让任何人获得90 +%。沮丧,我想出了这个例子。我希望它能帮助别人。 (这肯定帮助了我!; - )

import sys, traceback

traceback_template = '''Traceback (most recent call last):
  File "%(filename)s", line %(lineno)s, in %(name)s
%(type)s: %(message)s\n''' # Skipping the "actual line" item

# Also note: we don't walk all the way through the frame stack in this example
# see hg.python.org/cpython/file/8dffb76faacc/Lib/traceback.py#l280
# (Imagine if the 1/0, below, were replaced by a call to test() which did 1/0.)

try:
    1/0
except:
    # http://docs.python.org/2/library/sys.html#sys.exc_info
    exc_type, exc_value, exc_traceback = sys.exc_info() # most recent (if any) by default

    '''
    Reason this _can_ be bad: If an (unhandled) exception happens AFTER this,
    or if we do not delete the labels on (not much) older versions of Py, the
    reference we created can linger.

    traceback.format_exc/print_exc do this very thing, BUT note this creates a
    temp scope within the function.
    '''

    traceback_details = {
                         'filename': exc_traceback.tb_frame.f_code.co_filename,
                         'lineno'  : exc_traceback.tb_lineno,
                         'name'    : exc_traceback.tb_frame.f_code.co_name,
                         'type'    : exc_type.__name__,
                         'message' : exc_value.message, # or see traceback._some_str()
                        }

    del(exc_type, exc_value, exc_traceback) # So we don't leave our local labels/objects dangling
    # This still isn't "completely safe", though!
    # "Best (recommended) practice: replace all exc_type, exc_value, exc_traceback
    # with sys.exc_info()[0], sys.exc_info()[1], sys.exc_info()[2]

    print
    print traceback.format_exc()
    print
    print traceback_template % traceback_details
    print

在此查询的具体答案中:

sys.exc_info()[0].__name__, os.path.basename(sys.exc_info()[2].tb_frame.f_code.co_filename), sys.exc_info()[2].tb_lineno

答案 3 :(得分:25)

以下是显示异常发生位置的行号的示例。

import sys
try:
    print(5/0)
except Exception as e:
    print('Error on line {}'.format(sys.exc_info()[-1].tb_lineno), type(e).__name__, e)

print('And the rest of program continues')

答案 4 :(得分:5)

您无需导入回溯即可实现:

try:
    func1()
except Exception as ex:
    trace = []
    tb = ex.__traceback__
    while tb is not None:
        trace.append({
            "filename": tb.tb_frame.f_code.co_filename,
            "name": tb.tb_frame.f_code.co_name,
            "lineno": tb.tb_lineno
        })
        tb = tb.tb_next
    print(str({
        'type': type(ex).__name__,
        'message': str(ex),
        'trace': trace
    }))

输出:

{

  'type': 'ZeroDivisionError',
  'message': 'division by zero',
  'trace': [
    {
      'filename': '/var/playground/main.py',
      'name': '<module>',
      'lineno': 16
    },
    {
      'filename': '/var/playground/main.py',
      'name': 'func1',
      'lineno': 11
    },
    {
      'filename': '/var/playground/main.py',
      'name': 'func2',
      'lineno': 7
    },
    {
      'filename': '/var/playground/my.py',
      'name': 'test',
      'lineno': 2
    }
  ]
}

答案 5 :(得分:0)

没有任何导入,但是与导入的模块不兼容:

try:
    raise TypeError("Hello, World!")  # line 2
except Exception as e:
    print(
        type(e).__name__,          # TypeError
        __file__,                  # /tmp/example.py
        e.__traceback__.tb_lineno  # 2
    )

$ python3 /tmp/example.py
TypeError /tmp/example.py 2

要重申,这在import或模块中有效,因此,如果您执行import X; try: X.example();,则文件名和行号将指向包含{{ 1}},而不是错误的行 X.example()。如果有人知道如何轻松地从最后一个堆栈跟踪行中获取文件名和行号(我期望像X.example()之类的东西,但运气不好),请改进此答案。