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...
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'', (), [], {},...
之所以在写法二中可以用if直接判断列表a是否为空,是因为对于list来说,它没有内建方法__bool__(),而有内建方法__len__(),最后通过判断list长度是否为 0 来得出true或者false的,一旦为空,则判断结果为false
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 of any list if s == []: sub_set = True # Check if 's' is equal to 'l';...
编写一个名为 check-season 的函数,它接受一个月份参数并返回季节:秋季、冬季、春季或夏季。 编写一个名为 calculate_slope 的函数,它返回线性方程的斜率 二次方程计算如下:ax² + bx + c = 0。编写一个计算二次方程解集的函数,solve_quadratic_eqn。 声明一个名为 print_list 的函数。它将一个列表作为参...
Python: Checking if a 'Dictionary' is empty doesn't seem to work - Stack Overflow https://stackoverflow.com/questions/23177439/python-checking-if-a-dictionary-is-empty-doesnt-seem-to-work python - How do I check if a list is empty? - Stack Overflow https://stackoverflow.com/questions...
You can pass many options to the configure script; run./configure --helpto find out more. On macOS case-insensitive file systems and on Cygwin, the executable is calledpython.exe; elsewhere it's justpython. Building a complete Python installation requires the use of various additional third-pa...
list.reverse()和list.sort()分别表示原地倒转列表和排序(注意,元组没有内置的这两个函数)。 reversed()和sorted()同样表示对列表/元组进行倒转和排序,reversed()返回一个倒转后的迭代器(上文例子使用list()函数再将其转换为列表);sorted()返回排好序的新列表。 列表和元组存储方式的差异 前面说了,列表和元组最...
is:检查两个变量是否指向同一对象内存中 ==:比较两个对象的值 first_list = [1, 2, 3] second_list = [1, 2, 3] # 比较两个值 print(first_list == second_list) # True # 是否指向同一内存 print(first_list is second_list) # False third_list = first_list print(third_list is first_lis...
``` # Python script to check the status of a website import requests def check_website_status(url): response = requests.get(url) if response.status_code == 200: # Your code here to handle a successful response else: # Your code here to handle an unsuccessful response ``` 说明: 此...