电源变换适用于非独立源码

As we have discussed in the previous post (Python None keyword), that "None" is a keyword which can be used to assign a null value to a variable or to check whether a variable contains any value or not.

正如我们在上一篇文章中讨论的( Python None关键字 )， “ None”是可用于为变量分配空值或检查变量是否包含任何值的关键字。

Example:

例：

Here, we have 3 variables a, b and c, a is being assigned with "Hello", b is being assigned with "None" and c is being assigned with 10.

在这里，我们有3个变量a ， b和c ， a分配给“ Hello” ， b分配给“ None” ， c分配给10 。

We are testing whether variables have a value or None, if they have values, we are printing their values.

我们正在测试变量是否具有值或无，如果它们具有值，我们将打印其值。

# python code for not None test
# variable 1 with value
a = "Hello"
# variable 2 with None
b = None
# variable 3 with value 
c = 10
# performing is not None test 
if a is not None:
print("value of a: ", a)
else:
print("\'a\' contains None")
if b is not None:
print("value of b: ", b)    
else:
print("\'b\' contains None")
if c is not None:
print("value of c: ", c)
else:
print("\'c\' contains None")

Output

输出量

value of a:  Hello
'b' contains None
value of c:  10

翻译自: https://www.includehelp.com/python/not-none-test.aspx

电源变换适用于非独立源码