Question

marks = {}
for _ in range(int(input())):
  line = input().split()
  marks[line[0]] = list(map(float, line[1:]))
print('%.2f' %(sum(marks[input()])/3))

我是python的新手。你能告诉我这段代码的意思吗？
我听不懂。

Answer 1

此代码的作用：



 # initialized a dictionary type names marks
 marks = {}

 # The input() method will pause and wait for someone to input data in the command line

 # The range() method will create an array of int given the a number 
 #   example: range(5) will create [0, 1, 2, 3, 4] 
 # In this case it will take the string returned from input() convert it to an integer
 # and use that as the value.

 # The for loop will, run as many times as there are elements "in" the array created
 # the _ is just a silly variable name the developer used because
 # he is not using the value in the array anywhere.
 for _ in range(int(input())):
   # Get a new input from the user
   # split the string (it uses spaces to cut the string into an array)
   #   example if you type "one two three" it will create ["one", "two", "three"]
   # store the array in the variable line
   line = input().split()
   # add/replace the element using the first string in the line as key
   # line[0] is the first element in the array
   # lint[1:] is the array containing all the elements starting at index 1 (the second element)
   # map() is a function that will call the function float on each elements of the array given. basically building an array with the values [float(line[1]), float(line[2])…]
   # list will convert the array into a list.
   marks[line[0]] = list(map(float, line[1:]))

 # this last line asks the user for one more value
 # gets the list in the marks dictionary using the value inputed by the user
 # calculates the sum of all the floats in that list. 
 # divides it by 3 and prints the results as a floating point number with 2 decimal places.
 print('%.2f' %(sum(marks[input()])/3))

我无法理解代码。谁能帮我吗？

1 个答案: