[bug] インデックスアクセスでリスト範囲外アクセス起こりうるのでは about arbitrage_crypto HOT 6 CLOSED

#!/usr/bin/env python
idx = [0, 0, 0]
arr = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'] # 長さ10の任意のリスト
for i in range(10):
    idx[0] += 1
    print(arr[idx[0]])

b
c
d
e
f
g
h
i
j
Traceback (most recent call last):
  File "foo.py", line 6, in <module>
    print(arr[idx[0]])
IndexError: list index out of range

idx = np.zeros(3).astype(int)

amount1 = np.cumsum(ask1[:, 1] * ask2[-1][0])
amount2 = np.cumsum(ask2[:, 1])
amount3 = np.cumsum(bid3[:, 1])

ratio = 0
value = 0

for i in range(10):
    new_ratio = (
        bid3[:, 0][idx[2]] / (ask1[:, 0][idx[0]] * ask2[:, 0][idx[1]]))
    if new_ratio < threshold:
        break
    ratio = new_ratio
    value = np.min([amount1[idx[0]], amount2[idx[1]], amount3[idx[2]]])
    idx[np.argmin([
        amount1[idx[0]], amount2[idx[1]], amount3[idx[2]]])] += 1
return (ratio, value)