You can usetry/exceptto catch theKeyErrorraised byan_empty_set.pop(), or check the set first to make sure it's not empty: ifs: value = s.pop()else:# whatever you want to do if the set is empty Share Copy link Improve this answer ...
se = set() se.pop() print(se) # KeyError: 'pop from an empty set' 1. 2. 3. # 随机删除,有则删除且有返回值,如果集合中没有元素,那么报错 1. remove # 指定删除remove和discard # remove """ Remove an element from a set; it must be a member. If the element is not a member, ra...
>>> set2 set() >>> set2.pop() Traceback (most recent call last): File "<pyshell#293>", line 1, in <module> set2.pop() KeyError: 'pop from an empty set' >>> >>> #discard()删除一个元素且不返回,与remove()不同的是,如果该元素不存在,不会抛出异常,do nothing >>> set1 ...
>>> s.pop() # 抛出异常 Traceback (most recent call last): File "<stdin>", line 1, in <module> KeyError: 'pop from an empty set' 5.union方法 作用:用于合并多个集合,相当于多个集合做并集运算 原型:set.union(...) -> set 参数:任意多个可迭代类型数据 返回值: 返回新的集合 示例: >>>...
在编写一个 Python 程序时,由于需要在设备连接时更新设备标签并且将其传递给 Exchange,开发者遇到了一个问题:IndexError: pop from empty list。这表明在尝试从 Welcome.dev_label 列表中弹出元素时,该列表为空。 2、解决方案 为了解决这个问题,需要确保在从 Welcome.dev_label 列表中弹出元素之前,已经将设备标签添...
Attempting this with an iterator will just return the same exhausted iterator object used in the previous iteration pass, making it appear like an empty container. 可变数据(immutable) 列表(list) 字典(dictionary) 集合(set)。 不可变数据(immutable)...
print(s2.pop()) #{2} print("===pop",s2) #{1} 随机删除集合中的元素2,并且返回{2} # Remove andreturnan arbitrarysetelement. # Raises KeyErrorifthesetisempty. # s2=set() # print(s2.pop()) #报错 KeyError:'pop from an empty set'#2-3删除元素--指定删除 ...
print(S.pop())# The updated setprint("Updated set is", S) 输出: rishav ram rahim Updated set is {'aakash', 'ajay'} 另一方面,如果集合为空,则返回TypeError,如以下程序所示。 # Python code to illustratepop() method# on an empty setS = {}# Popping three elements and printing themprint...
is_empty: raise StackEmptyException('Error: trying to pop element from an empty stack!') node = self._top self._top = self._top.next return node.value def top(self): return self._top.value if self._top else self._top def clear(self): while self._top: self.pop() def test(...
set_pop(PySetObject *so) { /* Make sure the search finger is in bounds */ Py_ssize_t i = so->finger & so->mask; setentry *entry; PyObject *key;assert (PyAnySet_Check(so)); if (so->used == 0) { PyErr_SetString(PyExc_KeyError, "pop from an empty set"); ...