如何修改列表理解中的外部变量？

Question

Python代码：

i: int = 1
table: list = [[i, bit, None, None ] for bit in h]
del i
del bit

预期行为：

i: int = 1
table: list = [[i++, bit, None, None ] for bit in h] # the i needs to be incremented by 1 per iteration
del i
del bit

Answer 1

在这种情况下，请使用

enumerate

:

h = '10010010'  # Undefined in OP example.  Just something to enumerate.
table = [[i, bit, None, None ] for i, bit in enumerate(h, start=1)]
for row in table:
    print(row)

输出：

[1, '1', None, None]
[2, '0', None, None]
[3, '0', None, None]
[4, '1', None, None]
[5, '0', None, None]
[6, '0', None, None]
[7, '1', None, None]
[8, '0', None, None]