无效的python语法问题（如果语句执行许多操作）

Question

我在python代码上遇到问题。我试图在if语句后增加和减少两个值。但是，这无法实现（错误：语法无效）。知道当我仅增加一个值（例如A_p）时，它会很好地工作。错误是否来自and运算符？是否可以在if语句后执行多种操作？

谢谢。

Omer

k1 = 0.2
k2 = 0.2 
Delta_t = 2


A_p = 4
B_p = 3


list_nm = [0.800, 0.801, 0.752, 0.661, 0.169, 0.956, 0.949, 0.003, 0.201, 0.291, 0.615, 0.131, 0.241, 0.685, 0.116, 0.241, 0.849]

for i in range(7):
    if list_nm[i] < (A_p/7):
        print("Particle A was choosen")
        if list_nm[i] < k1*Delta_t:
            A_p -= 1 and B_p += 1
        else:
            A_p = A_p and B_p = B_p
    elif list_nm[i] < (B_p/7):
        print("Particle B was choosen")
        if list_nm[i] < k2*Delta_t:
            A_p +=1 and B_p -=1
        else:
            A_p = A_p and B_p = B_p
    else:
        print("No choice was made")
        A_p = A_p and B_p = B_p
print(B_p)

Answer 1

A_p -= 1 and B_p += 1

不是有效的Python，and是用于组合布尔值的特定关键字，例如：

if a > 3 and a < 7:
    pass

您想要的是两个单独的语句：

A_p -= 1
B_p += 1

或者，如果您必须放在一行上（并且我会问为什么，您认为这是必要的），请根据您的喜好选择以下选项之一：

A_p -= 1 ; B_p += 1
(A_p, B_p) = (A_p - 1, B_p + 1)

---

此外，该行：

A_p = A_p and B_p = B_p

即使将其拆分为两个语句，实际上也无济于事。如果这是else:块中唯一的内容，您也可以将其与前面的else行一起完全删除。

换句话说，从以下内容开始：

(k1, k2, Delta_t) = (0.2, 0.2, 2)
(A_p, B_p) = (4, 3)

list_nm = [0.800, 0.801, 0.752, 0.661, 0.169, 0.956, 0.949, 0.003, 0.201, 0.291, 0.615, 0.131, 0.241, 0.685, 0.116, 0.241, 0.849]

for i in range(7):
    if list_nm[i] < (A_p / 7):
        print("Particle A was choosen")
        if list_nm[i] < k1 * Delta_t:
            A_p -= 1
            B_p += 1
    elif list_nm[i] < (B_p / 7):
        print("Particle B was choosen")
        if list_nm[i] < k2 * Delta_t:
            A_p += 1
            B_p -= 1
    else:
        print("No choice was made")
print(B_p)