python变量分配内存

Since, Python is a dynamic programming language so there is no need to declare such type of variable, it automatically declares when first time value assign in it.

由于Python是一种动态编程语言，因此无需声明此类变量，它会在首次分配值时自动声明。

Still, this is a common question asked by many programmers that can we declare any variable without any value?

尽管如此，这是许多程序员提出的一个常见问题， 我们可以声明没有任何值的任何变量吗？

The answer is: "Yes! We can declare such type of variable". To declare a variable without any variable, just assign None.

答案是：“是！我们可以声明这种类型的变量” 。 要声明不带任何变量的变量，只需分配None即可 。

Syntax:

句法：

variable_name = None

Example:

例：

num = None

Let’s understand through a program:

让我们通过一个程序来理解：

# Python program to declare a # variable without assigning any value # declare variable num = None# print the valueprint "value of num: ", num# checking variableif (num==None):	print "Nothing"else:		print "Something"	# assign some valuenum = 100# print the valueprint "value of num: ", num# checking variableif (num==None):	print "Nothing"else:		print "Something"

Output

输出量

value of num:  None    Nothing    value of num:  100    Something

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python变量分配内存