warnings.py 文件源码

def simplefilter(action, category=Warning, lineno=0, append=0):
    """Insert a simple entry into the list of warnings filters (at the front).

    A simple filter matches all modules and messages.
    'action' -- one of "error", "ignore", "always", "default", "module",
                or "once"
    'category' -- a class that the warning must be a subclass of
    'lineno' -- an integer line number, 0 matches all warnings
    'append' -- if true, append to the list of filters
    """
    assert action in ("error", "ignore", "always", "default", "module",
                      "once"), "invalid action: %r" % (action,)
    assert isinstance(lineno, int) and lineno >= 0, \
           "lineno must be an int >= 0"
    item = (action, None, category, None, lineno)
    if append:
        filters.append(item)
    else:
        filters.insert(0, item)