KeyError on weighted tasks

[glentsch]

Description of issue / feature request

The docs state you specify weights for callables: https://docs.locust.io/en/stable/writing-a-locustfile.html#tasks-attribute, by the tasks attribute being a dictionary. However you get a KeyError.

Expected behavior

A task should be selected.

Actual behavior

There is a KeyError when selecting a task:

File "/usr/local/lib/python3.6/site-packages/locust/core.py", line 358, in run
    self.schedule_task(self.get_next_task())
  File "/usr/local/lib/python3.6/site-packages/locust/core.py", line 419, in get_next_task
    return random.choice(self.tasks)
  File "/usr/local/lib/python3.6/random.py", line 258, in choice
    return seq[i]
KeyError: 38

This is occurring because self.tasks is a dictionary, not a list. Instead it should use: random.choice(self.tasks.keys()) if self.tasks is a dict.

Environment settings (for bug reports)

• OS: macOS 10.13.6
• Python version: 3.6.4
• Locust version: 0.9.0

Steps to reproduce (for bug reports)

class MyTaskSet(TaskSet):
   def func1(self):
      #do something....
    tasks = {func1: 2, ...}

[dblakemore]

This isn't quite correct. tasks on a TaskSet class might be defined as a callable:int dict, but this is then parsed into a sequance in the TaskSetMeta class:

        if "tasks" in classDict and classDict["tasks"] is not None:
            tasks = classDict["tasks"]
            if isinstance(tasks, dict):
                tasks = six.iteritems(tasks)
            
            for task in tasks:
                if isinstance(task, tuple):
                    task, count = task
                    for i in xrange(0, count):
                        new_tasks.append(task)
                else:
                    new_tasks.append(task)

I suspect your issue is more related to the way in which you're defining your callables. Can you post / send me the actual code that is raising this error (not just a snippet)

[glentsch]

I refactored the code, and wrote a mockup of what I had done, though cannot reproduce the bug. I will close.