You can simply check if the List is empty with: ifnotmy_list:print("List is empty") This is using theTruth Value Testingin Python, also known as implicit booleaness or truthy/falsy value testing. Among other rules it defines that empty sequences and collections like'', (), [], {},...
a = []iflen(a) ==0:print("empty list") 写法二 Copy a = []ifnota:print("empty list") 这两种写法都很常见。那么问题来了,第一种写法用列表长度去判断列表为空可以理解,那么第二种写法直接去判断,这是怎么判断出来的呢? if 为了解决这个问题,我们首先需要重新认识一下if。关于 if 是用来做条件执...
A more explicit way to check if a list is empty is to use Python's built-inlen()function, which returns the number of items in a list. Here's how you can uselen()to check if a list is empty: my_list=[]iflen(my_list)==0:print("The list is empty")else:print("The list is...
2)Example 1: Initialize Empty List with Given Size using List Multiplication 3)Example 2: Initialize Empty List with Given Size using List Comprehension 4)Video, Further Resources & Summary If you want to learn more about these topics, keep reading!
我们使用条件语句来判断列表是否为空。如果列表为空(即列表的布尔值为 False),则输出 “The list is empty”;如果列表不为空(列表的布尔值为 True),则输出 “The list is not empty”。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 ifnot my_list:print("The list is empty")else:print("The li...
# Define a function named 'is_Sublist' that checks if list 's' is a sublist of list 'l' def is_Sublist(l, s): sub_set = False # Initialize a flag 'sub_set' to indicate whether 's' is a sublist of 'l # Check if 's' is an empty list; in this case, 's' is a sublist...
运行以上代码,将得到输出结果为:[‘apple’, ‘banana’, ‘orange’]。可以看到,新列表new_list中已经成功删除了原列表中的空值。 4. 状态图 下面使用mermaid语法标识出删除列表中空值的状态图: StartCheckRemoveEmptyValue 上述状态图描述了删除列表中空值的过程。从Start状态开始,程序首先会进入Check状态,然后根据...
if sys.version_info >= (3,): def __imul__(self: _S, n: int) -> _S: ... def __contains__(self, o: object) -> bool: ... def __reversed__(self) -> Iterator[_T]: ... def __gt__(self, x: List[_T]) -> bool: ... ...
当数据不应该被复制时,例如因为数据太大或者函数设计需要在原地更改数据以使调用者受益时,调用list()会很糟糕。在这种情况下,像isinstance(x, abc.MutableSequence)这样的运行时检查将是一个好方法。如果你担心得到一个无限生成器——这不是一个常见问题——你可以先调用len()来检查参数。这将拒绝迭代器,同时安全...
numbers = [2, 4, 6, 8, 1] for number in numbers: if number % 2 == 1: print(number) break else: print("No odd numbers") 如果找到了奇数,就会打印该数值,并且执行break语句,跳过else语句。没有的话,就不会执行break语句,而是执行else语句。 ▍2、从列表中获取元素,定义多个变量 my_list = ...