python - 将数据保存在 Python 的调用库(pyinvoke)的上下文变量中

Question

使用 Invoke library for Python ，我想先运行一个设置任务，在 context variable 中保存一些值然后所有以下任务都可以读取和使用。

The documentation is quite short on that topic , 然而, 它指出

A common problem task runners face is transmission or storage of values which are “global” for the current session - values loaded from configuration files (or other configuration vectors), CLI flags, values set by ‘setup’ tasks, etc.

(emphasis by me)

，所以这实际上应该是可能的。

但是，当我写这篇文章的时候，

from invoke import task

@task
def set_context(context):
    context.foo = 'bar'

@task
def read_context(context):
    print(context.foo)

然后通过 invoke read_context set_context 从命令行运行文件，然后我得到

Traceback (most recent call last):
  File "/usr/local/lib/python3.4/dist-packages/invoke/config.py", line 69, in __getattr__
    return self._get(key)
  File "/usr/local/lib/python3.4/dist-packages/invoke/config.py", line 113, in _get
    value = self.config[key]
  File "/usr/local/lib/python3.4/dist-packages/invoke/config.py", line 110, in __getitem__
    return self._get(key)
  File "/usr/local/lib/python3.4/dist-packages/invoke/config.py", line 113, in _get
    value = self.config[key]
KeyError: 'foo'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/invoke", line 11, in <module>
    sys.exit(program.run())
  File "/usr/local/lib/python3.4/dist-packages/invoke/program.py", line 270, in run
    self.execute()
  File "/usr/local/lib/python3.4/dist-packages/invoke/program.py", line 381, in execute
    executor.execute(*self.tasks)
  File "/usr/local/lib/python3.4/dist-packages/invoke/executor.py", line 113, in execute
    result = call.task(*args, **call.kwargs)
  File "/usr/local/lib/python3.4/dist-packages/invoke/tasks.py", line 111, in __call__
    result = self.body(*args, **kwargs)
  File "/home/jenkins/workspace/Deploy_Birmingham_URL_Service_on_Docker_host/deployment/tasks.py", line 14, in read_context
    print(context.foo)
  File "/usr/local/lib/python3.4/dist-packages/invoke/config.py", line 81, in __getattr__
    raise AttributeError(err)
AttributeError: No attribute or config key found for 'foo'

Valid keys: ['run', 'tasks']

Valid real attributes: ['from_data', 'run']

在 invoke 中将某些内容保存在上下文变量中并在其他任务中重复使用的正确方法是什么？我正在使用 Python 3.5.2 并在重要时调用 0.13.0。

---

future 用户须知:0.15 修复了这个问题(github bug link)

Answer 1

使用ctx.update。

from invoke import task

@task
def set_context(context):
    context.update({'foo': 'bar'})

@task
def read_context(context):
    print(context.foo) # => 'bar'