3、Python 对异常的操作

捕获所有错误

try:
    file = open("name.txt")
except Exception as e:
    print(' %s ' %e)
finally:
    file.close()

自定义打印出的错误信息（关键字raise）

try:
    raise NameError('helloError')
except NameError:
    print(' my custom error ')

上下文管理器

fd = open('name.txt')
try:
	for line in fd:
	print (line)
finally:
	fd.close()

使用上下文管理器写法：

with open('name.txt') as f:
	for line in f:
	print(line)