python變量分配內存

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是一種動態編程語言，因此無需聲明此類變量，它會在首次分配值時自動聲明。

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

盡管如此，這是許多程序員提出的一個常見問題， 我們可以聲明沒有任何值的任何變量嗎？

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！我們可以聲明這種類型的變量” 。 要聲明不帶任何變量的變量，只需分配None即可 。

Syntax:

句法：

 variable_name = None

Example:

例：

 num = None

Let’s understand through a program:

讓我們通過一個程序來理解：

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

Output

輸出量

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

翻譯自: https://www.includehelp.com/python/declare-any-variable-without-assigning-any-value.aspx

python變量分配內存