Closures

At work, I wrote a Python script which uses the multiprocessing module to process many servers in parallel. The code looks something like:

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def processServer(server):
    # Do work...

numParallelTasks = ...
servers = [...]
pool = multiprocessing.Pool(processes=numParallelTasks)
results = pool.map(processServer, servers)

I wanted to pass some extra state to processServer without using a global variable. My first attempt was to use a closure, so I wrote the following: