Python For Loops -枚举

Question

你能帮我做这个吗？尝试了下面的代码，但不起作用。我想打印出附加的输出。提前谢谢。

num_display = int(input('Please enter how many numbers you would like displayed: '))
inc_value = int(input('Please enter the increment value: '))
num_counter = 1
num_sequence = range(1, num_display + 1 , inc_value)
value_counter = range(1, num_counter, inc_value)

for each_num in num_sequence:
    print(f'Counter: {num_counter} value: {each_num}')
    num_counter = num_counter + 1
    value_counter = value_counter + 1
print("Bye.")

输出应该是什么样子？

Please enter how many numbers you would like displayed: 12
Please enter the increment value: 3
Counter: 1 value: 1
Counter: 2 value: 4
Counter: 3 value: 7
Counter: 4 value: 10
Counter: 5 value: 13
Counter: 6 value: 16
Counter: 7 value: 19
Counter: 8 value: 22
Counter: 9 value: 25
Counter: 10 value: 28
Counter: 11 value: 31
Counter: 12 value: 34
Bye.

为了满足其他条件，我对代码进行了更改，但在num_sequence = range(1，stop_value，inc_value) TypeError：' str‘对象中，将str转换为int:第11行后得到了这个错误。

我的代码：

num_display = input('Please enter how many numbers you would like displayed: ').strip()
inc_value = input('Please enter the increment value: ').strip()
zero_value = 0

if num_display.isdigit() and inc_value.isdigit():
    if int(num_display) != zero_value or int(inc_value) != zero_value:
        stop_value = int(num_display) * int(inc_value)
        num_sequence = range(1,stop_value,inc_value)
        for num_counter, each_num in enumerate(num_sequence):
                        print(f'Counter: {num_counter + 1} value: {each_num}')
        print('Bye.')
    else:
        print("I can't increment in steps of 0.")     

else:
    print('Positive non zero integers only please.')

我让它在下面使用，但它没有正确地打印另一个，请参见屏幕截图：

num_display = input('Please enter how many numbers you would like displayed: ').strip()
inc_value = input('Please enter the increment value: ').strip()
zero_value = 0

if num_display.isdigit() and inc_value.isdigit():
    if int(num_display) != zero_value and int(inc_value) != zero_value:
        stop_value = int(num_display) * int(inc_value)
        num_sequence = range(1, int(stop_value), int(inc_value))
        for num_counter, each_num in enumerate(num_sequence):
                        print(f'Counter: {num_counter + 1} value: {each_num}')
        print('Bye.')
    else:
        print("I can't increment in steps of 0.")     

else:
    print('Positive non zero integers only please.')

在另一个测试上工作但不打印5

Answer 1

您的代码有一些问题。每次迭代之后，range()都会通过inc_value自动增加计数器，所以不要在循环中手动更新计数器。

另外还有一个数学问题。如果要打印一个num_display乘以inc_value递增的数字，则计算最后一个数字(因此range()的end值)的公式是start_value + inc_value * num_display，而不是num_display + 1。在您的例子中，start_value是1。

要以pythonic方式获得迭代次数，请使用enumerate()。

num_display = int(input('Please enter how many numbers you would like displayed: '))
inc_value = int(input('Please enter the increment value: '))
start_value = 1
num_sequence = range(1, start_value + num_display * inc_value, inc_value)

for num_counter, each_num in enumerate(num_sequence):
    print(f'Counter: {num_counter + 1} value: {each_num}')
print("Bye.")

预期产出

Please enter how many numbers you would like displayed: 12
Please enter the increment value: 3
Counter: 1 value: 1
Counter: 2 value: 4
Counter: 3 value: 7
Counter: 4 value: 10
Counter: 5 value: 13
Counter: 6 value: 16
Counter: 7 value: 19
Counter: 8 value: 22
Counter: 9 value: 25
Counter: 10 value: 28
Counter: 11 value: 31
Counter: 12 value: 34
Bye.