log日志级别
软件内部要打印log日志，需要设计不同的日志级别。
举例
Scrapy
参考Logging — Scrapy 0.24.1 文档中就有：
Log levels
Scrapy提供5层logging级别:
1. CRITICAL - 严重错误(critical)
2. ERROR - 一般错误(regular errors)
3. WARNING - 警告信息(warning messages)
4. INFO - 一般信息(informational messages)
5. DEBUG - 调试信息(debugging messages)
scrapy.log.CRITICAL
严重错误的Log级别
scrapy.log.ERROR
错误的Log级别 Log level for errors
scrapy.log.WARNING
警告的Log级别 Log level for warnings
scrapy.log.INFO
记录信息的Log级别(生产部署时推荐的Log级别)
scrapy.log.DEBUG
调试信息的Log级别(开发时推荐的Log级别)
Supervisor
supervisor的log的日志级别：
Logging — Supervisor 3.3.4 documentation
| Config File Value | Output Code | Description |
|---|---|---|
| critical | CRIT | Messages that indicate a condition that requires immediate user attention, a supervisor state change, or an error in supervisor itself. |
| error | ERRO | Messages that indicate a potentially ignorable error condition (e.g. unable to clear a log directory). |
| warn | WARN | Messages that indicate an anomalous condition which isn’t an error. |
| info | INFO | Normal informational output. This is the default log level if none is explicitly configured. |
| debug | DEBG | Messages useful for users trying to debug process configuration and communications behavior (process output, listener state changes, event notifications). |
| trace | TRAC | Messages useful for developers trying to debug supervisor plugins, and information about HTTP and RPC requests and responses. |
| blather | BLAT | Messages useful for developers trying to debug supervisor itself. |