无法在for循环的升序和降序范围内打印答案

【问题标题】：Unable to print in both ascending and descending range in for loop无法在for循环的升序和降序范围内打印
【发布时间】：2019-02-18 05:46:08
【问题描述】：

我正在尝试在 for 循环中创建 if else 规则，但目前仅当起始值小于结束值时才会打印这些值。如果起始值大于结束值，我希望范围以降序打印。

我尝试了几个不同的选项，但理想情况下我尝试只使用两个 for 循环来创建代码。

for i in range(x,y+1):
    if (x<=y):
      print(i) 
    else:
     for i in range(y,x,-1):
      print(i)
count_odd = 0 
count_even = 0 
for n in range(x,y+1):
        if   n%2==0: 
             count_even = count_even+1 
        else: 
             count_odd = count_odd+1 
print("Number of even numbers :",count_even)
print("Number of odd numbers :",count_odd)

【问题讨论】：

标签： python for-loop

【解决方案1】：

如果x<y 在您的代码中添加一个条件，并相应地使用range 升序或降序：

x = 10
y = 2
count_odd = 0 
count_even = 0 
if x < y:
    for n in range(x,y+1):
        if n%2==0: 
            count_even = count_even+1 
        else: 
            count_odd = count_odd+1 
else:
    for n in range(x, y-1, -1):
        if n%2==0: 
            count_even = count_even+1 
        else: 
            count_odd = count_odd+1 

print("Number of even numbers :",count_even)
print("Number of odd numbers :",count_odd)

输出：

Number of even numbers : 5                                                                                                            
Number of odd numbers : 4

编辑

你的初始 for 循环应该是：

if (x<=y):
    for i in range(x,y+1):
        print(i) 
else:
    for i in range(x,y-1,-1):
        print(i)

【讨论】：

【解决方案2】：

您需要以不同方式处理它们，并在条件满足时调用特定函数。这是一个例子。

x = 1
y = 10


def descOrder(x,y):
    count_even = 0
    count_odd = 0
    for i in range(x, y-1, -1):
        if i % 2 == 0:
            count_even = count_even + 1
        else:
            count_odd += 1
        print(i)
    print ("Even:",count_even, "Odd:",count_odd)


def asceOrder(x, y):
    count_even = 0
    count_odd = 0
    for i in range(x ,y+1):
        if i % 2 == 0:
            count_even += 1
        else:
            count_odd += 1
        print(i)
    print ("Even:",count_even, "Odd:",count_odd)


if x > y:
    descOrder(x, y)
else:
    asceOrder(x, y)

【讨论】：