完整模板
首先，直接给出完整的使用，有以下模板方便直接套用，以读入命令行参数：
def parse_command_line_arguments():
# Import the required modules
import argparse
# Instantiate the parser
command_line_arguments_parser = argparse.ArgumentParser()
# TODO: ADD YOUR ARGUMENTS HERE
# Add positional arguments
command_line_arguments_parser.add_argument(
"my_positional_int_arg",
type=int,
help="This is a essential test integer argument",
default=3,
)
# Add optional arguments
command_line_arguments_parser.add_argument(
"--my_optional_string",
type=str,
help="This is a optional test string argument",
default="hello world",
)
# Add bool arguments(no argument value needed)
command_line_arguments_parser.add_argument(
"-v",
"--verbose",
action="store_true",
help="When True, prints out more information",
)
# Parse the arguments
command_line_args = command_line_arguments_parser.parse_args()
# Return the parsed arguments
return command_line_args
# TODO: USE IN YOUR CODE
# command_line_args = parse_command_line_arguments()
# print(command_line_args.your_argument_name)
在主代码中使用的参考如下：
command_line_args = parse_command_line_arguments()
# Print all arguments
print(command_line_args)
# Int arguments usage
print(f"Squared value of {command_line_args.my_positional_int_arg} is {command_line_args.my_positional_int_arg**2}")
# Bool arguments usage
if command_line_args.verbose:
print("This is a verbose print when --verbose is True")
具体解释
对于模板中存在的代码片段，有如下解释：
基本使用
# Import the lib
import argparse
# Instantiate the parser
command_line_arguments_parser = argparse.ArgumentParser()
# Parse the arguments
command_line_args = command_line_arguments_parser.parse_args()
此时无任何程序所需的参数需要输入，通过python <your_script>.py -h进行检验，应当输出如下：
hermanye@hermanye:~/test_ws$ python my_test.py -h
usage: my_test.py [-h]
optional arguments:
-h, --help show this help message and exit
添加参数
在实例化ArgumentParser后，使用add_argument()添加需要读取的参数，并指定它的名称、提示说明、参数变量类型、动作等。
位置参数
对于必须要输入的位置参数：
- 片段
# Add positional arguments
command_line_arguments_parser.add_argument(
"my_positional_int_arg",
type=int,
help="This is a essential test integer argument",
default=3,
)
- 示例代码
# Import the lib
import argparse
# Instantiate the parser
command_line_arguments_parser = argparse.ArgumentParser()
# Add positional arguments
command_line_arguments_parser.add_argument(
"my_positional_int_arg",
type=int,
help="This is a essential test integer argument",
default=3,
)
# Parse the arguments
command_line_args = command_line_arguments_parser.parse_args()
# Print all arguments
print(command_line_args)
# Int arguments usage
print(f"Squared value of {command_line_args.my_positional_int_arg} is {command_line_args.my_positional_int_arg**2}")
- 测试
python my_test.py 5
# Results
Namespace(my_positional_int_arg=5)
Squared value of 5 is 25
可选参数
对于可选参数，需要在参数名前加上--
- 片段
# Add optional arguments
command_line_arguments_parser.add_argument(
"--my_optional_string",
type=str,
help="This is a optional test string argument",
default="hello world",
)
- 示例代码
# Import the lib
import argparse
# Instantiate the parser
command_line_arguments_parser = argparse.ArgumentParser()
# Add optional arguments
command_line_arguments_parser.add_argument(
"--my_optional_string",
type=str,
help="This is a optional test string argument",
default="hello world",
)
# Parse the arguments
command_line_args = command_line_arguments_parser.parse_args()
# Print all arguments
print(command_line_args)
# String arguments usage
print(command_line_args.my_optional_string)
- 测试
# Test 1
python my_test.py
# Test 2
python my_test.py --my_optional_string "This is my test string."
# Results 1
Namespace(my_optional_string='hello world')
hello world
# Results 2
Namespace(my_optional_string='This is my test string.')
This is my test string.
对于不需要具体参数值，而只有True和False的参数，通常使用以下方式赋值：
# Add bool arguments(no argument value needed)
command_line_arguments_parser.add_argument(
"-v",
"--verbose",
action="store_true",
help="When True, prints out more information",
)
# Bool arguments usage
if command_line_args.verbose:
print("This is a verbose print when --verbose is True")
使用参数
参数解析后，可以读取整个参数表，也可以读取参数表中具体参数的值：
# Parse the arguments
command_line_args = command_line_arguments_parser.parse_args()
# Print all arguments
print(command_line_args)
# Int arguments usage
print(f"Squared value of {command_line_args.my_positional_int_arg} is {command_line_args.my_positional_int_arg**2}")
# String arguments usage
print(command_line_args.my_optional_string)
# Bool arguments usage
if command_line_args.verbose:
print("This is a verbose print when --verbose is True")
