Dictionary with costs by weight

Question

today I would like to embed shipping price table to python dictionary and I have not idea how to start.

What I have?

I have table with shipping costs and zones.

    +-----------+------+---------+--------+
    |  weight   | Asia | America | Europe |
    +-----------+------+---------+--------+
    | 0-500     |   10 |      15 |      5 |
    | 501-1000  |   13 |      18 |      8 |
    | 1001-2000 |   16 |      21 |     11 |
    +-----------+------+---------+--------+

What I have tried?

shipping_costs =    [

                        {
                            "min_w":    0,
                            "max_w":    500,
                            "asia":     10,
                            "america":  15,
                            "europe":   5
                        },
                        {
                            "min_w":    501,
                            "max_w":    1000,
                            "asia":     13,
                            "america":  18,
                            "europe":   8
                        },
                        {
                            "min_w":    1001,
                            "max_w":    2000,
                            "asia":     16,
                            "america":  21,
                            "europe":   11
                        }

                    ]

product_weight = 600

for zone in shipping_costs:
    if zone['min_w'] <= product_weight <= zone['max_w']:
        print('Asia: {}, America: {}, Europe: {}'.format(zone['asia'],zone['america'],zone['europe']))

And... And it works but I have doubts about search method. Is it properly way? Or is better tool to finding ranges?

Tim Pietzcker · Answer 1 · 2016-07-06T12:41:20.033

2

It's quite OK, but you need to correct your edge conditions - check for "less than or equal" instead of "less than", or cases like 500 will produce incorrect results:

if zone['min_w'] <= product_weight <= zone['max_w']:

Also, there's a typo - the closing parenthesis of the print function must of course come after the .format() method:

    print('Asia: {}, America: {}, Europe: {}'.format(zone['asia'],zone['america'],zone['europe']))

Also possible:

   print('Asia: {asia}, America: {america}, Europe: {europe}'.format(**zone))

edited Jul 06 '16 at 12:41

answered Jul 06 '16 at 11:51

Tim Pietzcker

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1

Oh thank you. What is that `0` which you typed in second possible format? – user3041764 Jul 06 '16 at 12:01
Ok now I understand everything – user3041764 Jul 06 '16 at 12:31
I had to leave for a while, sorry. But in the meantime I remembered how to properly access items of a dictionary in a format string. – Tim Pietzcker Jul 06 '16 at 12:43
But now it isn't that obvious for me. Can you shortly explain what you did? – user3041764 Jul 06 '16 at 12:51
1

`**` is the "keyword unpacking" operator, allowing you to pass a dictionary into a function or method as if you had provided all of its contents manually. See http://stackoverflow.com/q/1769403/20670 for some good explanations. – Tim Pietzcker Jul 06 '16 at 13:30

Dictionary with costs by weight

What I have?

What I have tried?

1 Answers1