CODEWITHSUNDEEP
pythondictionarynestednested-loops
Chris McGonigle
Chris McGonigle

Reputation: 3

Issue trying to return key and values inside a nested dictionary

First time poster here. I'm trying to create a simple conversion program on Python for a project I am working on as part of a course I am enrolled in.

I am trying to return the conversion for a number of length units based on a starting unit. To do this I am trying to use nested dictionaries. It has to be via a CLI terminal so i'm not allowed to use ttinker or anything like that to provide a GUI.

I am trying to return it in the format:

x centimetres converted equals:

x kilometres
x metres
x miles etc.

Instead I am getting this return with my current version of code(although I do expect it to return like this, but this is the closest to the result I want I have came yet):

x centimetres converted equals:
x
x
x
kilometres
metres
miles

My code at present looks like:

            len_selection = pyip.inputMenu(["Nanometre", "Micrometre", "Millimetre", "Centimetre", "Metre", "Kilometre", "Inch", "Foot", "Yard", "Mile", "Nautical Mile"], numbered=True)
            print("\nEnter the number of your required unit\n")
            len_value = pyip.inputNum("\nPlease enter the length to convert:")

            length_conversion_factors = {
                'kilometre': {'metre': 0.001, 'centimetre': 0.00001, 'millimetre': 0.000001,
                'micrometre': 0.000000001, 'nanometre': 0.000000000001, 'mile': 1.60934,
                'yard': 0.000914397727272727, 'foot': 0.000304799242424242, 'inch': 2.53999368686869,
                'nautical mile': 1.852},

                'metre': {'kilometre': 1000, 'centimetre': 0.01, 'millimetre': 0.001, 'micrometre': 0.000001,
                'nanometre': 0.000000001, 'mile': 1609.34, 'yard': 0.914397727272727, 'foot': 0.304799242424242,
                'inch': 0.0253999368686869, 'nautical mile': 1852},

                'centimetre': {'kilometre': 100000, 'metre': 100, 'millimetre': 0.1,
                'micrometre': 0.0001, 'nanometre': 0.0000001, 'mile': 160934,
                'yard': 91.4397727272727, 'foot': 30.4799242424242, 'inch': 2.53999368686869,
                'nautical mile': 185200}}

            length_key = len_selection.lower()

            print(f"\n{len_value} {len_selection}s converted equals:")

            if length_key in length_conversion_factors:
                for value in length_conversion_factors[length_key]:
                    conv_value = len_value * float(length_conversion_factors[length_key][value])
                    print(conv_value)
                for key in length_conversion_factors[length_key]:
                    print(key)

I have spent a day and a half on this already and I am pulling my hair out at this point.

I have tried the likes of 'for key, value in length_conversion_factors[length_key]:'so it all runs in the one for loop and I get a Value error saying too much to be unpacked. I also tried unpacking the keys first, storing them in a variable and then using a print statement but no joy with it either.

I've tried using 'return key' and 'return conv_value' and then using a separate print statement on those but cant seem to get it to work at all.

I' know I'm probably missing something very simple. many thanks in advance

Upvotes: 0

Views: 35

Answers (1)

kcsquared
kcsquared

Reputation: 5409

Python lets you print more than one thing in a statement:

if length_key in length_conversion_factors:
    for value in length_conversion_factors[length_key]:
        conv_value = len_value * float(length_conversion_factors[length_key][value])
        print(conv_value, value)

This is giving me output like:

1 kilometres converted equals:
0.001 metre
1e-05 centimetre
1e-06 millimetre
1e-09 micrometre

which appears to be what you wanted. You can even replace the final print statement with an f-string, just like the one that appears already in the code: print(f"{conv_value} {value}s")

Upvotes: 1

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