Invalid syntax python problem (if statement many actions) - if-statement

Question

I am encountering a problem on my python code. I'm trying to increment and decrement two values after an if statement. However, this couldn't be achieved (Error: invalid syntax). Knowing that when I increment only a single value (e.g. A_p), it works well. Does the error come from the and operator? Is there a way to perform multiple actions after an if statement?
Thank you.
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
is not valid Python, and is a specific keyword used for combining booleans, such as:
if a > 3 and a < 7:
pass
What you're after instead is two separate statements:
A_p -= 1
B_p += 1
or, if you must have it on a single line (and I'd question why you think this is necessary), one of the following, depending on what you prefer:
A_p -= 1 ; B_p += 1
(A_p, B_p) = (A_p - 1, B_p + 1)
In addition, the line:
A_p = A_p and B_p = B_p
even when you split it into two statements, is effectively doing nothing. You may as well remove it totally, along with the else: line preceding it if that's the only thing in the else block.
In other words, start with something this:
(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)