I have a dictionary, and I want to use the items (key,value) to generate a single string, which I will pass argument to another script on the command line.
Snippet illustrates further:
args = { 'arg1': 100, 'arg2': 234 }
I want to create the string:
--arg1=100 --arg2=234
from the dictionary.
The naive (expensive) way to do that would be to loop through the items in the dictionary, building the string as I went along.
Is there a more pythonic way of doing this?
You need a loop, but you can do it concisely:
" ".join("--%s=%s" % item for item in args.iteritems())
(for Python 2. For Python 3, change iteritems to items)
' '.join('--%s=%s' % (k, v) for (k, v) in args.items())
Since you plan to pass it to another script and probably do so using the subprocess module: Do not create a string at all!
args = ['/path/to/your/script'] + ['--%s=%s' % item for item in args.iteritems()]
You can pass this array to subprocess.call() (or .Popen() etc.) and by not using an argument string you can ensure that even spaces, quotes, etc. won't cause any issues.
