Python traceback，显示错误发生的行，即使没有显示完整的 traceback

Question

如何确保在不包括整个回溯的情况下打印出失败的实际行？追溯对我来说可能太长了，所以我也把它全部打印出来。

此代码仅打印函数 a 和 b 中的错误，但我想查看实际错误发生在函数 d 中。

import traceback
def a():
    try:
        return b();
    except:
        print traceback.format_exc(2)

def b():
    return c();

def c():
    return d();

def d():
    x = 1/0

a()

Answer 1

你可以这样做:

import sys
import traceback

def a():
    try:
        return b();
    except:
        _, _, tb = sys.exc_info()
        print traceback.format_list(traceback.extract_tb(tb)[-1:])[-1]

或者你自己格式化字符串:

import sys
import traceback

def a():
    try:
        return b();
    except:
        _, _, tb = sys.exc_info()
        filename, lineno, funname, line = traceback.extract_tb(tb)[-1]
        print '{}:{}, in {}\n    {}'.format(filename, lineno, funname, line)

---

• sys.exc_info()

This function returns a tuple of three values that give information about the exception that is currently being handled (...) If no exception is being handled anywhere on the stack, a tuple containing three None values is returned. Otherwise, the values returned are (type, value, traceback).

• traceback.extract_tb(traceback[, limit])

Return a list of up to limit “pre-processed” stack trace entries extracted from the traceback object traceback. It is useful for alternate formatting of stack traces. If limit is omitted or None, all entries are extracted. A “pre-processed” stack trace entry is a quadruple (filename, line number, function name, text) representing the information that is usually printed for a stack trace. The text is a string with leading and trailing whitespace stripped; if the source is not available it is None.

• traceback.format_list(list)

Given a list of tuples as returned by extract_tb() or extract_stack(), return a list of strings ready for printing. Each string in the resulting list corresponds to the item with the same index in the argument list. Each string ends in a newline; the strings may contain internal newlines as well, for those items whose source text line is not None.