debug.py 文件源码

def format_exception(tb_type=None, tb_value=None, tb=None):
    """
    Get the usual traceback information, followed by a listing of all the
    local variables in each frame.
    Based on:
    code.activestate.com/recipes/52215-get-more-information-from-tracebacks
    """
    import sys
    import traceback
    if tb_type is None:
        tb_type = sys.exc_type
    if tb_value is None:
        tb_value = sys.exc_value
    if tb is None:
        tb = sys.exc_info()[2]
    retval = traceback.format_exception(tb_type, tb_value, tb) + ["\n"]
    while tb.tb_next:
        tb = tb.tb_next
    stack = []
    f = tb.tb_frame
    while f:
        stack.append(f)
        f = f.f_back
    stack.reverse()
    retval.append("Local variables (most recent frame last):\n")
    for frame in stack:
        retval.append(" Frame %s, File \"%s\", line %s:\n" % (frame.f_code.co_name,
                                                              frame.f_code.co_filename,
                                                              frame.f_lineno))
        for key, value in frame.f_locals.items():
            if key.startswith("__"):
                continue
            #We have to be careful not to cause a new error in our error
            #handler! Calling str() on an unknown object could cause an
            #error we don't want.
            try:
                line = "  %s = %s\n" % (key, str(value))
            except:
                line = "  %s = %s\n" % (key, "<ERROR PRINTING VALUE>")
            retval.append(line)
    return retval