如何使用 if-else 语句在多个列表中插入相等数量的值？

Question

有一个数字列表，其中包含一些随机数。我正在对这些数字应用条件并进行一些计算并将结果值存储在多个列表中。但我面临的唯一问题是我无法在所有列表中存储相同数量的数字。假设如果该列表的条件不满足，那么0 应该在那里，但这在我的程序中没有发生。在我的程序中，数字列表是：number = [10, 9, 14, 17, -2, -3, 18, 25]，条件如下：

1. 如果 num == 0
2. 如果 0
3. 如果 12
4. 如果 15
5. 如果数字 > 20
6. 如果数字

多个列表是：

firstList = []
secondList = []
thirdList = []
forthList = []
fifthList = []
sixthList = []

我的方法：

 number = [10, 9, 14, 17, -2, -3, 18, 25]
firstList = []
secondList = []
thirdList = []
forthList = []
fifthList = []
sixthList = []
for num in number:
    if num ==0:
        firstList.append(0)
    else:
        firstList.append(0)

    if 0 < num <= 12:
        cal = num * 2
        secondList.append(cal)
    else:
        secondList.append(0)

    if 12 <= num <= 15:
        cal = num * 2
        cal2 = num * 4
        secondList.append(cal)
        thirdList.append(cal2)
    else:
        thirdList.append(0)
    if 15 < num <= 20:
        cal = num * 2
        cal2 = num * 4
        cal3 = num * 6
        secondList.append(cal)
        thirdList.append(cal2)
        forthList.append(cal3)
    else:
        forthList.append(0)
    if num > 20:
        cal = num * 2
        cal2 = num * 4
        cal3 = num * 6
        cal4 = num * 4
        secondList.append(cal)
        thirdList.append(cal2)
        forthList.append(cal3)
        fifthList.append(cal4)
    else:
        fifthList.append(0)

        if num < 0:
             cal5 = num * 10
             sixthList.append(cal5)
        else:
            sixthList.append(0)

print("list1: " , firstList)
print("list2: " , secondList)
print("list3: " , thirdList)
print("list4: " , forthList)
print("list5: " , fifthList)
print("list6: " , sixthList)

输出：

list1:  [0, 0, 0, 0, 0, 0, 0, 0]
list2:  [20, 18, 0, 28, 0, 34, 0, 0, 0, 36, 0, 50]
list3:  [0, 0, 56, 0, 68, 0, 0, 0, 72, 0, 100]
list4:  [0, 0, 0, 102, 0, 0, 108, 0, 150]
list5:  [0, 0, 0, 0, 0, 0, 0, 200]
list6:  [0, 0, 0, 0, -20, -30, 0]

期望的输出：

list1:  [0, 0, 0, 0, 0, 0, 0, 0]
list2:  [20, 18, 28, 34, 0, 0, 36, 50]
list3:  [0, 0, 56, 68, 0, 0, 72, 100]
list4:  [0, 0, 0, 102, 0, 0, 108, 150]
list5:  [0, 0, 0, 0, 0, 0, 0, 200]
list6:  [0, 0, 0, 0, -20, -30, 0, 0]

Answer 1

这是一个快速的解决方案，你用零初始化所有列表并使用索引来更新列表：

number = [10, 9, 14, 17, -2, -3, 18, 25]
firstList = [0] * len(number)
secondList = [0] * len(number)
thirdList = [0] * len(number)
forthList = [0] * len(number)
fifthList = [0] * len(number)
sixthList = [0] * len(number)
for i, num in enumerate(number):

# firstList has 0 anyway
#     if num == 0:
#         firstList[i] = 0


    if 0 < num <= 12:
        cal = num * 2
        secondList[i] = cal

    if 12 < num <= 15:
        cal = num * 2
        cal2 = num * 4
        secondList[i] = cal
        thirdList[i] = cal2

    if 15 < num <= 20:
        cal = num * 2
        cal2 = num * 4
        cal3 = num * 6
        secondList[i] = cal
        thirdList[i] = cal2
        forthList [i]= cal3

    if num > 20:
        cal = num * 2
        cal2 = num * 4
        cal3 = num * 6
        cal4 = num * 8
        secondList[i] = cal 
        thirdList[i] = cal2
        forthList[i] = cal3
        fifthList[i] = cal4
    else:
        if num < 0:
            cal5 = num * 10
            sixthList[i] = cal5


print("list1: " , firstList)
print("list2: " , secondList)
print("list3: " , thirdList)
print("list4: " , forthList)
print("list5: " , fifthList)
print("list6: " , sixthList)

输出：

list1:  [0, 0, 0, 0, 0, 0, 0, 0]
list2:  [20, 18, 28, 34, 0, 0, 36, 50]
list3:  [0, 0, 56, 68, 0, 0, 72, 100]
list4:  [0, 0, 0, 102, 0, 0, 108, 150]
list5:  [0, 0, 0, 0, 0, 0, 0, 200]
list6:  [0, 0, 0, 0, -20, -30, 0, 0]

Answer 2

尝试这样的事情，使用列表推导。首先关注每个列表，而不是条件。另请注意else 0 将在不满足条件的情况下填充为 0。

numbers = [10, 9, 14, 17, -2, -3, 18, 25]

firstList = [0]*len(numbers)
secondList = [n*2 if n > 0 else 0 for n in numbers]
thirdList = [n*4 if n>=12 else 0 for n in numbers]
fourthList = [n*6 if n>15 else 0 for n in numbers]
fifthList = [n*4 if n>20 else 0 for n in numbers]
sixthList = [n*10 if n<0 else 0 for n in numbers]

print(firstList)
print(secondList)
print(thirdList)
print(fourthList)
print(fifthList)
print(sixthList)

输出：

[0, 0, 0, 0, 0, 0, 0, 0]
[20, 18, 28, 34, 0, 0, 36, 50]
[0, 0, 56, 68, 0, 0, 72, 100]
[0, 0, 0, 102, 0, 0, 108, 150]
[0, 0, 0, 0, 0, 0, 0, 100]
[0, 0, 0, 0, -20, -30, 0, 0]

Answer 3

考虑到您想要来自均匀分布的数字，这意味着您获得的所有数字都有相同的概率出现，您可以执行以下操作：

import numpy as np

firstList = [0 for i in range(0,8)]
secondList = np.random.uniform(0,11,8)
thirdList = np.random.uniform(12,14,8)
forthList = np.random.uniform(15,19,8)
fifthList = np.random.uniform(20,1000,8)
sixthList = np.random.uniform(-100,0,8)

样本均匀分布在半开区间[低、高）（包括低，但不包括高）。换句话说，给定区间内的任何值都同样可能被uniform绘制。