如果满足条件

Question

我有以下python代码：

for i in range(large_number):
  # compute a_i
  if a_i is condition:
    # Need to make change here for the file open
    f = open('file.log', wb)
    # more computations proceeding. Cannot use break

现在，由于我的代码复杂性，我只能通过

needs_fopen = False
for i in range(large_number):
  # compute a_i
  if a_i is condition:
    needs_fopen = True

if needs_fopen is True:
  f = open('file.log', wb)

我不想执行第二种方法才能实现打开文件。如何实现第一个方法，但只有满足条件时才打开文件一次？

Answer 1

f = None
for i in range(large_number):
  # comput a_i
  if a_i is condition and not f:
    f = open('file.log', wb)

Answer 2

使用任何（）具有生成器理解：

if any(i is condition for i in range(number)):
  f = open('file.log', wb)