从整数列表中，获取最接近并小于给定值的数字

Question

I am writing a code in which i have to select an integer from a list which is not only closest to a given value but also less than it at the same time. How can i edit the code to meet both the conditions?

I have tried to use the in-built min() function which i have found on this site . It gives me that integer which is closest to a given value regardless of the integer being greater or smaller than given value.

def price(my_list,real_price):
   closest_number=min(my_list, key=lambda x:abs(x-real_price))
   return closest_number

my_list=[101,90,70]
real_price=100
closest_number=price(my_list,real_price)
print(closest_number)

For the code above, I want the output to be 90 but I am getting 101

Answer 1

Instead of min you should get the max of the numbers that are less than real_price :

def price(my_list,real_price):
    return max(price for price in my_list if price <= real_price)

With this change, your code would output: 90

Answer 2

What you have is close; you just need to accept only numbers that are less than real_price :

def price(my_list, real_price):
   closest_number = min((number for number in my_list if number < real_price), key=lambda x: abs(x - real_price))
   return closest_number

my_list = [101,90,70]
real_price = 100
closest_number = price(my_list, real_price)
print(closest_number)

Output:

90

Answer 3

Using List comprehension and max you can get 90.

def price(my_list,real_price):
   return max([x for x in my_list if ( x <= real_price )])

my_list=[101,90,70]
real_price=100
closest_number=price(my_list,real_price)
print(closest_number)