Buggy python submission (verdict: Runtime Error):
import numpy as np

N = input().split()

Nsum = list()
op = list()
for i in range(len(N)-1):
    if N[i].isdigit():
        op.append(float(N[i]))
    else:
        if N[i] == "+":
            Nsum.append(op[0] + op[1])
            op = list()
        elif N[i] == "-":
            Nsum.append(op[0] - op[1])
            op = list()
        elif N[i] == "*":
            Nsum.append(op[0] * op[1])
            op = list()


if N[-1] == "+":
    print(np.sum(Nsum))
elif N[-1] == "-":
    Nsub = Nsum[0]
    for n in Nsum[1:]:
        Nsub -= n
    print(Nsub)

elif N[-1] == "*":
    print(np.prod(Nsum))

Fixed submission:

o = list()
top = -1
for s in input().split():
    if s.isdigit():
        o.append(int(s))
        top += 1
    else:
        if s is "+":
            n = o[top]+o[top-1]
            o.pop(top)
            top-=1
            o.pop(top)
            top-=1
            o.append(n)
            top+=1
        if s is "-":
            n = o[top-1] - o[top]
            o.pop(top)
            top -= 1
            o.pop(top)
            top -= 1
            o.append(n)
            top+=1
        if s is "*":
            n = o[top]*o[top-1]
            o.pop(top)
            top -= 1
            o.pop(top)
            top -= 1
            o.append(n)
            top+=1


print(o[0])

Buggy python submission (verdict: Runtime Error):
import numpy as np

N = input().split()

Nsum = list()
op = list()
for i in range(len(N)):
    if N[i].isdigit():
        op.append(float(N[i]))
    else:
        if N[i] == "+":
            opSum = np.sum(op)
            op.clear()
            op.append(opSum)
        elif N[i] == "-":
            sub = op[0]
            for n in op[1:]:
                sub -= n
            op.clear()
            op.append(sub)
        elif N[i] == "*":
            opProd = np.prod(op)
            op.clear()
            op.append(opProd)


print(op[0])

Fixed submission:

o = list()
top = -1
for s in input().split():
    if s.isdigit():
        o.append(int(s))
        top += 1
    else:
        if s is "+":
            n = o[top]+o[top-1]
            o.pop(top)
            top-=1
            o.pop(top)
            top-=1
            o.append(n)
            top+=1
        if s is "-":
            n = o[top-1] - o[top]
            o.pop(top)
            top -= 1
            o.pop(top)
            top -= 1
            o.append(n)
            top+=1
        if s is "*":
            n = o[top]*o[top-1]
            o.pop(top)
            top -= 1
            o.pop(top)
            top -= 1
            o.append(n)
            top+=1


print(o[0])

Buggy python submission (verdict: Runtime Error):
import numpy as np

o = list()
for s in input().split():
    if s.isdigit():
        o.insert(0, int(s))
    else:
        if s is "+":
            o.append(o[0]+o[1])
            o.pop(0)
            o.pop(0)
        if s is "-":
            o.append(o[1] - o[0])
            o.pop(0)
            o.pop(0)
        if s is "*":
            o.append(o[0]*o[1])
            o.pop(0)
            o.pop(0)

print(o[0])

Fixed submission:

o = list()
top = -1
for s in input().split():
    if s.isdigit():
        o.append(int(s))
        top += 1
    else:
        if s is "+":
            n = o[top]+o[top-1]
            o.pop(top)
            top-=1
            o.pop(top)
            top-=1
            o.append(n)
            top+=1
        if s is "-":
            n = o[top-1] - o[top]
            o.pop(top)
            top -= 1
            o.pop(top)
            top -= 1
            o.append(n)
            top+=1
        if s is "*":
            n = o[top]*o[top-1]
            o.pop(top)
            top -= 1
            o.pop(top)
            top -= 1
            o.append(n)
            top+=1


print(o[0])