How to use python's logging library

Logging is a module used for logging in the Python standard library. It provides a concise but flexible way to record events in a program for subsequent debugging and analysis.

The basic steps for using the logging library are as follows:

Import the logging library

import logging

Configure the logger

logging.basicConfig(level=logging.INFO,
                    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')

The above code A basic logger is configured, the logging level is specified as INFO, and the logging format is specified.

Logging

logging.info("This is an info log")
logging.warning("This is a warning log")

When using the logging library, we can use different logging levels (such as DEBUG, INFO, WARNING, ERROR, CRITICAL) to record events of different severity . We can record different levels of logs to different files or locations by setting different loggers.

The following is a more complete example

import logging

# 配置日志记录器
logging.basicConfig(level=logging.INFO,
                    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
                    filename='example.log',
                    filemode='w')

# 定义一个函数
def divide(x, y):
    try:
        result = x / y
    except ZeroDivisionError:
        logging.error("Division by zero!")
    else:
        logging.info("Division result: %f", result)

# 记录日志
logging.info("Starting the program")
divide(10, 5)
divide(10, 0)
logging.warning("End of program")

In this example, we define a function called divide, which can calculate the division operation of two numbers. If the divisor is 0, an ERROR level log will be logged. Otherwise, an INFO level log containing the calculation results will be logged.

Finally, we recorded some logs in the main program. Among them, INFO level logs will be recorded to the example.log file, and WARNING level logs will be displayed on the console.

The above is the detailed content of How to use python's logging library. For more information, please follow other related articles on the PHP Chinese website!