What would be an effective way to call a function with arguments from a list in python

Question

My current code is similar to the following.

    def func(args):
        optionalparameters = ((args.split(':')[1]).split(' '))[1:]
        second_func(optionalparameters)

This assumes args is a colon-separated string; it takes the second half, splits it into space-delimited words and returns (a list of?) all but the first. The situation where more than one colon is included isn't yet handled, because I am new to the language.

Can the optional_parameters be passed not as a list? Since parameters are optional will the following be effective?

    def func(args):
        optionalparameters = ((args.split(':')[1]).split(' '))[1:]
        val1=val2=val3=None
        try:
            val1 = optionalparameters[0]
        except IndexError:
            pass
        try:
            val2 = optionalparameters[1]
        except IndexError:
            pass
        try:    
            val3 = optionalparameters[2]
        except IndexError:
            pass
        second_func(val1, val2, val3)

It seems likely that standard library modules might be able to do much of this. Any help in argument handling is highly appreciated.

I think you may just want `second_func(*optionalparameters)`. See https://stackoverflow.com/questions/36901/what-does-double-star-and-star-do-for-parameters — larsks, Aug 14 '17 at 20:14

score 0 · Accepted Answer · answered Aug 14 '17 at 20:47

0

You can unpack the values from the list:

optionalparameters = ((args.split(':')[1]).split(' '))[1:]
second_func(*optionalparameters)

or:

val1, val2, val3=((args.split(':')[1]).split(' '))[1:]    
second_func(val1, val2, val3)

answered Aug 14 '17 at 20:47

Netwave

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What would be an effective way to call a function with arguments from a list in python

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