python: calling constructor from dictionary?

Question

I'm not quite sure of the terminology here so please bear with me....

Let's say I have a constructor call like this:

machineSpecificEnvironment = Environment(
   TI_C28_ROOT = 'C:/appl/ti/ccs/4.1.1/ccsv4/tools/compiler/c2000',
   JSDB = 'c:/bin/jsdb/jsdb.exe',
   PYTHON_PATH = 'c:/appl/python/2.6.4',
)

except I would like to replace that by an operation on a dictionary provided to me:

keys = {'TI_C28_ROOT': 'C:/appl/ti/ccs/4.1.1/ccsv4/tools/compiler/c2000',
        'JSDB': 'c:/bin/jsdb/jsdb.exe',
        'PYTHON_PATH': 'c:/appl/python/2.6.4'}
machineSpecificEnvironment = Environment(
     ... what do I put here? it needs to be a function of "keys" ...
)

How can I do this?

score 5 · Accepted Answer · answered May 18 '10 at 14:20

5

machineSpecificEnvironment = Environment(**keys)

answered May 18 '10 at 14:20

Duncan

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In the documentation *duck* http://docs.python.org/tutorial/controlflow.html#keyword-arguments http://docs.python.org/tutorial/controlflow.html#unpacking-argument-lists – Rudi May 18 '10 at 14:29
various places, but the problem is knowing what to look for (and even then since there's no keyword it's tricky to search). Try http://docs.python.org/reference/expressions.html#calls for the formal function call syntax. – Duncan May 18 '10 at 14:31

score 3 · Answer 2 · answered May 18 '10 at 14:21

3

You can apply a dict as an argument list by the ** notation

machineSpecificEnvironment = Environment(**keys)

answered May 18 '10 at 14:21

Rudi

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python: calling constructor from dictionary?

2 Answers2