在python中创建基于“用户输入”的乘法表

Question

I am attempting to create a program asking the user for two inputs, from this a multiplication table will be created. For example, the user inputs 2 and 5.

Enter a starting integer of less than 1,000 and greater than 0: 2

Enter an ending integer greater than the first number and less than 1,000 : 5

I get something that looks like this:

     4     6     8    10

     6     9    12    15

     8    12    16    20

    10    15    20    25

However the math is wrong and I want 2-5 printed at the top and on the left side.

This is what I have so far:

    # In this program I will help you make a multiplication table
    print('In this program, I will help you make a multiplication table.')
    print('\n')

    # Ask user for a starting integer 
    start_value = int(input('Enter a starting integer of less than 1,000 and greater than 0: '))
    while start_value < 1 and start_value > 1000:
        start_value = int(input('Enter a starting integer of less than 1,000 and greater than 0: '))

    # Ask user for an ending integer
    end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))
    while end_value < 0 and end_value > 1000 and end_value > start_value:
        print('Invalid number')
        end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))

    for num1 in range(start_value, end_value+1):
        for num2 in range(start_value, end_value+1):
            table = (num1*num2)
            print(format(table, '6d'), end = '')
        print('\n')

I feel like something is up with the for-loop, I hope this makes sense, I greatly appreciate all the help!

Thank you!!!

Answer 1

In this code here, you get input, then start a loop. The input function is what gets user input, and you never get it again. You also have a logic error with your and s, they should be or s instead.

# this is your code, exactly as above
end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))
while end_value < 0 and end_value > 1000 and end_value > start_value:
    print('Invalid number')

Easiest fix:

end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))
while end_value < 0 or end_value > 1000 or end_value > start_value:
    print('Invalid number')
    end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))

But that duplicates the first line. So, a couple of other options:

while True:
    end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))
    if end_value < 0 or end_value > 1000 or end_value > start_value:
        break
    print('Invalid number')
   

Or, if you are on python 3.8+, you can use the := syntax here

while (end_value := int(input('Enter an ending integer greater than the first number and less than 1,000 : '))) < 0 or end_value > 1000 or end_value > start_value:
    print('Invalid number')
   

Answer 2

After working through this for a while, I did come up the answer to my own question. I want to post it here for anyone else who may be interested in the solution.

    # Max value as a constant
    MAX_VALUE = 1000

    # In this program I will help you make a multiplication table
    print('In this program, I will help you make a multiplication table.')
    print('\n')

    # Ask user for a starting integer and give parameters 
    start_value = int(input('Enter a starting integer of less than 1,000 and greater than 0: '))
    while start_value < 1 and start_value > MAX_VALUE:
        start_value = int(input('Enter a starting integer of less than 1,000 and greater than 0: '))
    print('\n')

    # Ask user for an ending integer and give parameters
    end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))
    while end_value < 0 and end_value > MAX_VALUE and end_value > start_value:
        print('Invalid number')
        end_value = int(input('Enter an ending integer greater than the first number and less than 1,000 : '))
    print('\n')

    # Format the top corner space
    print('      ', end = '')

    # Add a label row
    for label in range(start_value, end_value +1):    
        print(format(label, '6d'), end = '')
    print('\n')

    # Multiplication chart and left label column 
    for num1 in range(start_value, end_value+1):
        print(format(num1, '6d'), end = '')
        for num2 in range(start_value, end_value+1):
            table = (num1*num2)
            print(format(table, '6d'), end = '')
        print('\n')

This makes a clean Multiplication table for any range of numbers less than 1,000.

Cheers!