Question

I have a function that has several outputs, all of which “native”, i.e. integers and strings. For example, let’s say I have a function that analyzes a string, and finds both the number of words and the average length of a word.

In C/C++ I would use @ to pass 2 parameters to the function. In Python I’m not sure what’s the right solution, because integers and strings are not passed by reference but by value (at least this is what I understand from trial-and-error), so the following code won’t work:

def analyze(string, number_of_words, average_length):

    ... do some analysis ...

    number_of_words = ...    
    average_length = ...

If i do the above, the values outside the scope of the function don’t change. What I currently do is use a dictionary like so:

def analyze(string, result):

    ... do some analysis ...

    result['number_of_words'] = ...    
    result['average_length'] = ...

And I use the function like this:

s = "hello goodbye"
result = {}
analyze(s, result)

However, that does not feel right. What’s the correct Pythonian way to achieve this? Please note I’m referring only to cases where the function returns 2-3 results, not tens of results. Also, I’m a complete newbie to Python, so I know I may be missing something trivial here…

Thanks

Answer 1

python has a return statement, which allows you to do the follwing:

def func(input):
    # do calculation on input
    return result

s = "hello goodbye"
res = func(s)       # res now a result dictionary

but you don’t need to have result at all, you can return a few values like so:

def func(input):
    # do work
    return length, something_else         # one might be an integer another string, etc.

s = "hello goodbye"
length, something = func(s)