如何使用ifelse语句在多个列表中插入相等数量的值？

Question

有一个包含一些随机数的数字列表。我正在对这些数字应用条件，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等量的数字。假设如果该列表的条件没有满足，那么0应该在那里，但这不会发生在我的程序中。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<；num<；=十二,
3. 如果12<；num<；=十五
4. 如果15<；num<；=二十
5. 如果num>；二十
6. 如果num<；0

多个列表包括：

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

我的做法：

 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

尝试这样的方法，使用列表理解。首先关注每个列表，而不是条件。还要注意else 0，在不满足条件的情况下，它将用0填充

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)

产出：

[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 2

下面是一个快速解决方案，您可以用零初始化所有列表，并使用索引更新列表：

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 3

考虑到你想要一个均匀分布的数字，这意味着你得到的所有数字都有相同的概率，你可以做以下事情：

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放的区间[low，high）（包括low，但不包括high）。换句话说，给定区间内的任何值都同样可能由均匀分布得出