simpleopt 0.1.2a

用法示例

您只需定义一个函数，并有选择地注释 参数，相同的参数将在命令行上解析：

@annotation(command=str, interval=float, differences=bool,
            args=str, kwargs=str)
def watch(command, interval=2.0, differences=False, *args, **kwargs):
    print (command, interval, differences, args, kwargs)

if __name__ == '__main__':
    SimpleOpt(watch).run()

如果你把它保存在一个名为 watch.py并使其可执行：

$ watch.py "df -h"
('df -h', 2.0, False, (), {})

$ watch.py --interval 1.0 "df -h"
('df -h', 1.0, False, (), {})

$ watch.py --noverbose --differences "df -h"
('df -h', 1.0, True, (), {})

$ watch.py --foo bar --bar baz "df -h" quux quuux
('df -h', 2.0, False, ('quux', 'quuux'), {'foo': 'bar', 'bar': 'baz'})

另一个例子：

@annotation(foo={str:int})
def example(foo):
    return foo

$ example.py --foo a:1,b:2,c:3
{'a': 1, 'c': 3, 'b': 2}

$ example.py a:1,b:2,c:3
{'a': 1, 'c': 3, 'b': 2}

工作细节

命令行参数分为以下两种类型之一：（i）选项 参数和（ii）位置参数。

1. option arguments have the form –OPTION or –OPTION=VALUE where OPTION is the argument name and VALUE is an optional value given to that argument.
2. positional arguments are those that are not option arguments.

命令行参数分配给函数的形式 参数不同于python在python中分配输入参数的方式 代码。

在命令行上运行python脚本时，命令行参数是 分配给函数的形式参数如下：

• For each formal parameter, there is a slot which will be used to contain the value of the argument assigned to that parameter.

• Each slot is either ‘empty’ or ‘filled’. Slots which had values assigned to them are ‘filled’, otherwise they are ‘empty’.

• Initially, all slots are marked ‘empty’.

• Option arguments are assigned first, followed by positional arguments.

• For each option argument:

  o If there is a parameter with the same name as the option argument, then

  the argument value is assigned to that parameter slot. However, if the parameter is already filled, then that is an error.

  o Otherwise, if there is a ‘keyword dictionary’ argument, the argument is

  added to the dictionary using the keyword name as the dictionary key, unless there is already an entry with that key, in which case it is an error.

  o Otherwise, if there is no keyword dictionary, and no matching named

  parameter, then it is an error.

• 对于每个位置参数：

  o Attempt to bind the argument to the first unfilled parameter slot that

  has no default value. If the slot is not a vararg slot, then mark the slot as ‘filled’.

  o Otherwise, if the next unfilled slot is a vararg slot then all remaining

  positional arguments are placed into the vararg slot.

• 最后：

  o If the vararg slot is not yet filled, assign an empty tuple as its

  value.

  o If the keyword dictionary argument is not yet filled, assign an empty

  dicionary as its value.

  o For each remaining empty slot: if there is a default value for that

  slot, then fill the slot with the default value. If there is no default value, then it is an error.

当发生错误时，将打印有关错误的消息。