详解python中absl包的使用

### 1. 安装
 
pip install absl-py
 
### 2. 代码实例1
 
vim my_app.py
 
from absl import app
from absl import flags
 
FLAGS = flags.FLAGS
 
# Flag names are globally defined!  So in general, we need to be
# careful to pick names that are unlikely to be used by other libraries.
# If there is a conflict, we'll get an error at import time.
## 字符串类型，定义缺省值，以及说明
flags.DEFINE_string('name', 'Jane Random', 'Your name.')
 
## 整数类型，最小值为0
flags.DEFINE_integer('age', None, 'Your age in years.', lower_bound=0)
 
## 布尔类型
flags.DEFINE_boolean('debug', False, 'Produces debugging output.')
 
## 枚举类型，定义取值范围
flags.DEFINE_enum('job', 'running', ['running', 'stopped'], 'Job status.')
 
 
def main(argv):
    if FLAGS.debug:
        print('non-flag arguments:', argv)
    print('Happy Birthday', FLAGS.name)
    if FLAGS.age is not None:
        print('You are %d years old, and your job is %s' % (FLAGS.age, FLAGS.job))
 
 
if __name__ == '__main__':
    app.run(main)
 
## 运行，传入参数,一下命令等价
python3 my_app.py --name=zheng --age=18 --debug=True --job=stopped
python3 my_app.py --name zheng --age 18 --debug=True --job stopped
python3 my_app.py -name zheng -age 18 --debug=True -job stopped
python3 my_app.py -name zheng -age 18 --debug=True -job stopped
 
### 3. 示例代码2
vim my_app2.py
 
from absl import app
from absl import flags
from absl import logging
 
# 声明命令行参数
FLAGS = flags.FLAGS
flags.DEFINE_string("input_file", "input.txt", "Input file name")
flags.DEFINE_string("output_file", "output.txt", "Output file name")
 
def process_file(input_file, output_file):
    logging.info(f"Processing input file: {input_file} to output file: {output_file}")
    try:
        with open(input_file, 'r') as infile, open(output_file, 'w') as outfile:
            for line in infile:
                # 示例字符串处理：将每一行的字母转换为大写并写入输出文件
                outfile.write(line.upper())
        logging.info("Processing complete.")
    except Exception as e:
        logging.error(f"Error processing files: {e}")
 
def main(argv):
    # 解析命令行参数
    flags.FLAGS(argv)
    input_file = FLAGS.input_file
    output_file = FLAGS.output_file
    process_file(input_file, output_file)
 
if __name__ == "__main__":
    app.run(main)
 
## 运行
python3 my_app2.py