为什么Python的定量和变量界限不清

Question

考试Python变量与定量的选择题，一直做不对！
题目如下
POUND = "£"
DOLLAR = "$"
CONVERSION_DOLLAR_TO_POUND = 0.82
dollars_to_convert_str = input("How many whole dollars do you want to convert? ")
dollars_to_convert_int = int(dollars_to_convert_str)
equivalent_pounds = dollars_to_convert_int * CONVERSION_DOLLAR_TO_POUND
output_text = DOLLAR + dollars_to_convert_str + ' = ' + POUND + str(equivalent_pounds)
print (output_text)

请回答，
1.以上代码中，哪一个是变量（可多选）（）?
A.DOLLAR
B.POUND
C.CONVERSION_DOLLAR_TO_POUND
D.input
E.dollars_to_convert_str
F.dollars_to_convert_int
G.equivalent_pounds
H.output_text
I.print

2.以上代码中，哪一个是常量（可多选）（）?
A.DOLLAR
B.POUND
C.CONVERSION_DOLLAR_TO_POUND
D.input
E.dollars_to_convert_str
F.dollars_to_convert_int
G.equivalent_pounds
H.output_text
I.print

Answer 1

input、print和int()是内置函数，这不是变量，其他都是变量
POUND = "£" #str变量
DOLLAR = "$" #str变量
CONVERSION_DOLLAR_TO_POUND = 0.82 #float变量
dollars_to_convert_str = input("How many whole dollars do you want to convert? ") #str变量
dollars_to_convert_int = int(dollars_to_convert_str) #int变量
equivalent_pounds = dollars_to_convert_int * CONVERSION_DOLLAR_TO_POUND #float变量
output_text = DOLLAR + dollars_to_convert_str + ' = ' + POUND + str(equivalent_pounds) #str变量
print (output_text)
至于常量，python里没有常量的概念，只有程序员之间的约定，全大写表示常量
但是语法并不支持这样做，你还是可以随时修改它的值