traceback.py 文件源码

def extract_stack(f=None, limit=None):
    """Extract the raw traceback from the current stack frame.

    The return value has the same format as for extract_tb().  The
    optional 'f' and 'limit' arguments have the same meaning as for
    print_stack().  Each item in the list is a quadruple (filename,
    line number, function name, text), and the entries are in order
    from oldest to newest stack frame.
    """
    if f is None:
        try:
            raise ZeroDivisionError
        except ZeroDivisionError:
            f = sys.exc_info()[2].tb_frame.f_back
    if limit is None:
        if hasattr(sys, 'tracebacklimit'):
            limit = sys.tracebacklimit
    list = []
    n = 0
    while f is not None and (limit is None or n < limit):
        lineno = f.f_lineno
        co = f.f_code
        filename = co.co_filename
        name = co.co_name
        linecache.checkcache(filename)
        line = linecache.getline(filename, lineno, f.f_globals)
        if line: line = line.strip()
        else: line = None
        list.append((filename, lineno, name, line))
        f = f.f_back
        n = n+1
    list.reverse()
    return list