rfind(sub [,start [,end]]) -> int Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation
the return value is the same object. | | Method resolution order: | str | basestring | object | | Methods defined here: | | __add__(...) | x.__add__(y) <==> x+y | | __contains__(...) | x.__contains__(y) <==> y in x | | __eq__(...) | x.__eq__(y)...
Example of Out-of-Range Access: my_list = [10, 20, 30]print(my_list[3])# Attempt to access the fourth element In this example,my_listcontains three elements, so the highest valid positive index is 2 (my_list[2]). Attempting to accessmy_list[3]results in anIndexErrorbecause there ...
如果没有匹配项则返回-1) """ S.rfind(sub[, start[, end]]) -> int Return the highest index in S where substring sub is found, such that sub is contained within S[start:end].
索引值,可以指定索引范围来查找,查找不到会报错 def index(self, value start=None, stop=None): # real signature unknown; restored from __doc__ """ L.index(value, [start, [stop]]) -> integer -- return first index of value. Raises ValueError if the value is not present. """ return...
| L.index(value, [start, [stop]]) -> integer -- return first index of value. | Raises ValueError if the value is not present. | | insert(...) -- More -- 这里我们看到了关于 list 这个类,Python 提供的所有方法,可以直接调用,例如统计列表中单词 hello 的个数: >>>a="hello,world,...
value in cfg.IMAGE_PATHS.items(): if isinstance(value, list): images = [] for...
When using a generator, all of the values are generated on the fly. Functions become generators by using the yield keyword to return a value. The value that each yield returns is analogous to an element in a list or a set. In many situations, yield is used within a loop, automatically...
超出此范围则IndexError。 例: >>> city='Boston' >>> print city[6] Traceback (most recent call last): File "<pyshell#11>", line 1, in <module> print city[6] IndexError: string index out of range 字符串分割 格式如下: string[start:end]...
>>> x = list(range(10)) #创建列表>>>importrandom>>>random.shuffle(x) #把列表中的元素打乱顺序>>>x [0,7, 5, 9, 1, 2, 4, 8, 6, 3]>>>x[0] 0>>> x[1]7 >>> x[-1]3 >>> x[-2]6 del命令删除列表、字典等可变序列中的部分元素,而不能删除元组、字符串等不可变序列中的...