CODEWITHSUNDEEP
pythonarraysfunctionif-statement
user2734012
user2734012

Reputation: 43

function that takes in and returns multiple values

Say I have a function that calculates and returns an value:

h = 4.13566733*10**-15
c = 2.99792458*10**(8+9)


def func(x):
    for i in w:
        A = h*c/i
    return A


w = [1]
print func(w)

Fine. But if w is a larger array, say:

w = [1 ,2, 3, 4]

The func returns for the last value in w (4). Understandebly as that is the last item in the for-loop. But how can I make the func return an array with all 4 values, something like:

[1239, 619, 413, 309]

??

Upvotes: 1

Views: 64

Answers (4)

Paul
Paul

Reputation: 6737

You can use map, for example.

h = 4.13566733*10**-15
c = 2.99792458*10**(8+9)

def func(x):
  return h*c/x

w = [1,2,3]
print map(func, w)

Will return [1239.8418743309974, 619.9209371654987, 413.2806247769991]

And you can use more elegant way (as for me):

h = 4.13566733*10**-15
c = 2.99792458*10**(8+9)
w = [1,2,3]
result = map(lambda (x): h*c/x, w)

Is returns also [1239.8418743309974, 619.9209371654987, 413.2806247769991].

Upvotes: 0

dm03514
dm03514

Reputation: 55942

this is similar to what at @mu posted, but it seems like your function is operating on single values that are not connected together and might be more flexible implemented as only taking a number as a param.

h = 4.13566733*10**-15
c = 2.99792458*10**(8+9)

def func(x):
  return h*c / x

w = [1,2,3,4]
print([func(x) for x in w])

Upvotes: 1

Andy
Andy

Reputation: 50540

Make your A a list and append each result to that list

h = 4.13566733*10**-15
c = 2.99792458*10**(8+9)


def func(x):
    A = []
    for i in w:
        A.append(h*c/i)
    return A


w = [1,2,3,4]
print func(w)

This outputs:

[1239.8418743309974, 619.92093716549869, 413.2806247769991, 309.96046858274934]

Upvotes: 1

Anshul Goyal
Anshul Goyal

Reputation: 76847

Python supports passing multiple arguments, and returning multiple values. That said, you can change your code to:

def func(w):
    return [h*c/i for i in w]

If you now call this, you can get the required array:

>>> w = [1 ,2, 3, 4]
>>> func(w)
[1239.8418743309974, 619.9209371654987, 413.2806247769991, 309.96046858274934]

As for calling with multiple arguments and returning multiple examples, consider the following example method, which takes 2 inputs and returns 3 outputs:

>>> def get_product_modulo_dividend(x, y):
...     return x*y, x%y, x/y
>>> get_product_modulo_dividend(100, 10)
(1000, 0, 10)

Upvotes: 3

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