# Copyright 2014 Brett Slatkin, Pearson Education Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Preamble to mimick book environment
import logging
from pprint import pprint
from sys import stdout as STDOUT
# Example 1
from threading import Lock
lock = Lock()
with lock:
print('Lock is held')
Lock is held
# Example 2
lock.acquire()
try:
print('Lock is held')
finally:
lock.release()
Lock is held
# Example 3
import logging
logging.getLogger().setLevel(logging.WARNING)
def my_function():
logging.debug('Some debug data')
logging.error('Error log here')
logging.debug('More debug data')
# Example 4
my_function()
# Example 5
from contextlib import contextmanager
@contextmanager
def debug_logging(level):
logger = logging.getLogger()
old_level = logger.getEffectiveLevel()
logger.setLevel(level)
try:
yield
finally:
logger.setLevel(old_level)
# Example 6
with debug_logging(logging.DEBUG):
print('Inside:')
my_function()
print('After:')
my_function()
Inside: After:
# Example 7
with open('my_output.txt', 'w') as handle:
handle.write('This is some data!')
# Example 8
@contextmanager
def log_level(level, name):
logger = logging.getLogger(name)
old_level = logger.getEffectiveLevel()
logger.setLevel(level)
try:
yield logger
finally:
logger.setLevel(old_level)
# Example 9
with log_level(logging.DEBUG, 'my-log') as logger:
logger.debug('This is my message!')
logging.debug('This will not print')
# Example 10
logger = logging.getLogger('my-log')
logger.debug('Debug will not print')
logger.error('Error will print')