初学者 Python 代码问题
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Beginner Python Code Issues
提问by REDDY
5.2 Write a program that repeatedly prompts a user for integer numbers until the user enters 'done'. Once 'done' is entered, print out the largest and smallest of the numbers. If the user enters anything other than a valid number catch it with a try/except and put out an appropriate message and ignore the number. Enter the numbers from the book for problem 5.1 and Match the desired output as shown.
5.2 编写一个程序，反复提示用户输入整数，直到用户输入“完成”。输入“完成”后，打印出最大和最小的数字。如果用户输入的不是有效数字的任何内容，则使用 try/except 捕获它并发出适当的消息并忽略该数字。输入书中问题 5.1 的数字并匹配所需的输出，如图所示。
Here is my Code:
这是我的代码：
largest = None
smallest = None
while True:
inp = raw_input("Enter a number: ")
if inp == "done" : break
try:
num = float(inp)
except:
print "Invalid input"
if smallest is None:
smallest = num
elif num < smallest:
smallest = num
elif num > largest:
largest = num
continue
print "Maximum is", largest
print "Minimum is", smallest
******Please let me know the Logic errors in this CODE*****
******请让我知道此代码中的逻辑错误*****
回答by NightShadeQueen
A: You never assign largest away from being None.
答：你永远不会分配最大的远离 None 。
B: On the case that float(inp) fails, you still try to continue on. You shouldn't. While you canmove those if/elif statements into the try block, I'd recommend against that, because you then run the risk of accidentally catching something you shouldn't. Instead, use try/except's much neglected elseblock.
B：在 float(inp) 失败的情况下，您仍然尝试继续。你不应该。虽然您可以将那些 if/elif 语句移到 try 块中，但我建议您不要这样做，因为您可能会冒着意外捕获不应该捕获的内容的风险。相反，使用 try/except 被忽视的else块。
In the same line, it's good practice only except the error you want to and not all errors.
在同一行中，除了您想要的错误而不是所有错误之外，这是一种很好的做法。
C: No continue necessary
C：不需要继续
largest = None
smallest = None
while True:
inp = raw_input("Enter a number: ")
if inp == "done" : break
try:
num = float(inp)
except ValueError: #and not all errors!
print "Invalid input"
else:
# This block will execute if no exception is caught.
# Yes, this is valid python.
if smallest is None: #first number!
smallest = num
largest = num
elif num < smallest:
smallest = num
elif num > largest:
largest = num
print "Maximum is", largest
print "Minimum is", smallest
回答by Shoua Iqbal
Write a program that repeatedly prompts a user for integer numbers until the user enters 'done'. Once 'done' is entered, print out the largest and smallest of the numbers. If the user enters anything other than a valid number catch it with a try/except and put out an appropriate message and ignore the number.
编写一个程序，反复提示用户输入整数，直到用户输入“完成”。输入“完成”后，打印出最大和最小的数字。如果用户输入的不是有效数字的任何内容，则使用 try/except 捕获它并发出适当的消息并忽略该数字。
largest = None
smallest = None
while True:
inp = raw_input("Enter a number: ")
if inp == "done":
break
try:
num = int(inp)
if smallest is None:
smallest = num
elif num < smallest:
smallest = num
elif num > largest:
largest = num
except:
print "Invalid input"
continue
print "Maximum is", largest
print "Minimum is", smallest
error if mismatch appears after execution
如果执行后出现不匹配则出错
回答by Rohit Joshi
largest = None
smallest = None
while True:
inp = raw_input("Enter a number: ")
if inp == "done" : break
try:
num = int(inp)
except:
print "Invalid input"
continue
if smallest is None:
smallest = num
elif num < smallest:
smallest = num
if largest is None:
largest = num
elif num > largest:
largest = num
print "Maximum is", largest
print "Minimum is", smallest
回答by Nada Sami
largest = None
smallest = None
while True:
num = raw_input("Enter a number:")
if num == "done": break
try:
nom = int(num)
except:
print "Invalid input"
continue
if largest is None:
largest = nom
elif nom > largest:
largest = nom
if smallest is None:
smallest = nom
elif nom < smallest:
smallest = nom
print "Maximum is", largest
print "Minimum is", smallest
回答by Rabins Sharma Lamichhane
You should include your logic in your try: block to run this program logically. It will run even if you put your logic inside the catch block.
您应该在 try: 块中包含您的逻辑以逻辑地运行此程序。即使您将逻辑放在 catch 块中，它也会运行。
Placing the logic (if/else) after the catch is not able to calculate your highest and lowest number for the number you entered before the Error caught.
在捕获之后放置逻辑（if/else）无法计算您在捕获错误之前输入的数字的最高和最低数字。
Correct Method
正确方法
largest = None
smallest = None
while True:
num = input("Enter a number: ")
if num == 'done': break
try:
ival = int(num)
# This block will execute if no exception is caught.
# Yes, this is valid python.
if smallest is None: #first number!
smallest = ival
largest = ival
elif ival largest:
largest = ival
except ValueError: #and not all errors!
print ('Invalid input')
continue
print('Maximum is', largest)
print('Minimum is', smallest)
Wrong Method
错误的方法
largest = None
smallest = None
while True:
num = input("Enter a number: ")
if num == 'done': break
try:
ival = int(num)
except ValueError:
print ('Invalid input')
continue
if smallest is None:
smallest = ival
largest = ival
elif ival largest:
largest = ival
print('Maximum is', largest)
print('Minimum is', smallest)
回答by Manish Kumar
Code:
代码：
largest = None
smallest = None
while True:
num = input("Enter a number: ")
if num == "done":
break
try:
n = int(num)
if smallest is None or n < smallest:
smallest = n
if largest is None or n > largest:
largest = n
except ValueError:
# num cannot be converted to an int
print ("Invalid input")
print("Maximum is", largest)
print("Minimum is", smallest)
Output:
输出：
Invalid input
Maximum is 10
Minimum is 2
回答by Vikrant
Try this code ....
试试这个代码....
largest = None
smallest = None
while True:
num = input("Enter a number: ")
if num == "done" :
break
try:
inp=float(num)
except:
print("Invalid input")
continue
for value in [7,2,10,4]:
if largest is None:
largest = value
elif value>largest:
largest=value
print("Maximum is", largest)
for value in [7,2,10,4]:
if smallest is None:
smallest = value
elif value < smallest:
smallest=value
print("Minimum is", smallest)
回答by jv02
Here is the correct answerenter image description here
这是正确答案在此处输入图片说明
largest = None smallest = None
最大 = 无 最小 = 无
inp_list = [] while True: inp = raw_input("Enter a number: ") if inp == "done": break else: inp_list.append(inp)
inp_list = [] while True: inp = raw_input("Enter a number:") if inp == "done": break else: inp_list.append(inp)
for num in inp_list:
try:
num = int(num)
if smallest is None:
smallest = num
if num > largest :
largest = num
elif num < smallest :
smallest = num
except:
print ('Invalid input')
对于 inp_list 中的 num：尝试：num = int(num) 如果最小的是 None：最小 = num 如果 num > 最大：最大 = num elif num < 最小 = num 除了：
打印（'无效输入'）
print ("Maximum is", int(largest)) print ("Minimum is", int(smallest))
打印（“最大值”，整数（最大））打印（“最小值”，整数（最小））
回答by user11242194
largest = None
smallest = None
while True:
inp = raw_input("Enter a number: ")
if inp == "done" : break
try:
num = int(inp)
except ValueError: #and not all errors!
print ("Invalid input")
else:
# This block will execute if no exception is caught.
# Yes, this is valid python.
if smallest is None: #first number!
smallest = num
largest = num
elif num < smallest:
smallest = num
elif num > largest:
largest = num
print ("Maximum is", largest)
print ("Minimum is", smallest)
回答by Alessander Oliveira
#by Aless
largest = None
smallest = None
while True:
num = input("Enter a number: ")
if num == "done" : break
try:
intNum = int(num)
except ValueError:
#print('Error: Invalid input', num)
print('Invalid input')
continue
else:
if (largest < intNum): largest = intNum
if (smallest > intNum) or (smallest is None): smallest = intNum
print("Maximum", largest)
print("Minimum", smallest)
