regex在linux log4j文件中工作不正常?

我有一个由log4j生成的日志文件,我想用regex标识一个特定的行,我在regex101中测试过它。

下面是一个例子,它与regex101匹配:

regex = r"(Batch name): (.*?) (started)"
test_str = "Batch name: AS_ValueOnly started"

但是当我在python中迭代行时,这个日志文件不能与regex匹配。我进一步挖掘,发现问题来自 re.match 函数,当行到达时不匹配,

import re
log = "test.log"
with open(log, 'rb') as f:
    for line in f.readlines():
        if re.match(r"Batch name", line):
            print "found by regex"
            break
        if "Batch name" in line:
            print 'found by in line'
            break

以下是运行结果:

$python gen_split_log.py

found by in line

Process finished with exit code 0

你知道吗?