如何有效跟踪最大用户输入值？

Question

I need to find the largest number the user input but I can not define the largest as a number, like I defined "largest = -9999999", any suggestions? the "clargest" is to count how many time the largest number occurs

largest = -9999999

clargest = 0

while num != 0 :
    num = input("Enter your number or type 0 to end: ")
    if (num[0] == "-" and num[1:].isdigit()) or num.isdigit():
        num = int(num)
        if num != 0:
            if num > largest:
                clargest = 1
            elif num == largest:
                clargest = clargest + 1
            largest = max(largest,num)

Answer 1

You can start with the mathematically meaningful largest = float('-inf') , since the user is only allowed to enter (signed) integer numbers.

Side note: there is a much simpler way of writing your loop:

while num != 0 :
    num = input("Enter your number or type 0 to end: ")
    if (num[0] == "-" and num[1:].isdigit()) or num.isdigit():
        num = int(num)
        if num != 0:
    # ... keep track of largest

would be simpler as:

while True:
    try:
        num = int(input("Enter..."))
    except ValueError:
        continue
    if num == 0:
        break
    # ... keep track of largest

This use the recommended "it's better to ask forgiveness than permission" ( try ). It also removes the repetition of num != 0 . The test of "is this is number" is also more obvious. The need to have num be both a string and a number is also removed.

Answer 2

You have a few options. Here are two of them:

Option 1: Keep a list of all the numbers that the user input, sort it, and take the last one.

Option 2: (I think this is what you're trying to do) Keep track of the largest number that has been entered so far. Instead of defining largest as a large, negative number just keep around a boolean value that says if the input is the first number. The first number entered by the user is always the largest. For you, specifically, when clargest is 0 you can set largest to the user input.