如何在另一个函数中使用来自一个函数的输入？

Question

Can someone explain to me how I can use the input from one function in another? I have seen different questions but it doesn't make any sense to me: What is the purpose of the return statement?

I am trying to use the input here as the sides of a triangle. The next function should get that input and use it to get the perimeter. I want to be able to use those three sides later on in another function. This is what I have:

 #Input Func. using map
 def u_input_map():
     print("Enter the length of all sides")
     lengths  = input("Please enter enter the length of all sides in this
     format: a, b, c ").split(',')
     sides = list(map(int, lengths))
     print(sides[0],sides[1],sides[2])
     return(sides)
 u_input_map()

 # Triangle Perimeter Func.
 # P = a + b + c
 def perim(u_input_map):
     all_sides = (sides[0]+sides[1]+sides[2])
     print(all_sides)
     return sides
 perim(u_input_map)

I just want someone to point me in the right direction. I want to figure this out on my own so I don't need the code.

Answer 1

 #Input Func. using map.
 def u_input_map():
   print("Enter the length of all sides")
   lengths  = input("Please enter enter the length of all sides in this
   format: a, b, c ").split(',')
   sides = list(map(int, lengths))
   print(sides[0],sides[1],sides[2])
   return sides

 # Triangle Perimeter Func.
 # P = a + b + c
 def perim(sides):
   all_sides = (sides[0]+sides[1]+sides[2])
   return all_sides

 old_sides = u_input_map()
 perimeter = perim(old_sides)