python - 忽略基于子字符串的某些打印语句

Question

我有一些函数 f 调用了一些生成相当多不必要的打印语句的库。我不能简单地删除所有打印的值，因为这会使调试变得不可能。然而，有些事情总是打印出来，我确实想忽略。假设我想忽略(不显示)任何包含子字符串“substring”的打印行。有没有办法做一些事情:

def g():
    print('why is this substring being printed')
    return 1
def f():
    print('this should be printed')
    return g()
# now run with magic function
with IgnorePrints(substring='substring'):
    result = f()

如果此代码与 IgnorePrints 一起运行，它只会导致:

this should be printed

Answer 1

使用 contextlib.redirect_stdout :

import sys
from contextlib import redirect_stdout

class PrintFilter:
    def __init__(self, stream, substring):
        self.stream = stream
        self.substring = substring

    def write(self, txt):
        if self.substring not in txt:
            self.stream.write(txt)


my_filter = PrintFilter(stream=sys.stdout, substring="substring")

with redirect_stdout(my_filter):
    result = f()