Syntax to deploy for a dictionary comprehension with an if else condition, when also needing to cond-CodePudding

I have the following style of data i.e. a list of strings:

fruits_lst = ['Apple:Good','Banana:Off','Orange:Excellent','Blueberry:Excellent','Raspberry:Good']

I am looking to achieve this result, via comprehension in a single line of code:

{'APPLE:GOOD': 'Ripe',
 'BLUEBERRY:EXCELLENT': 'Ripe',
 'Banana:Off': 'Off',
 'ORANGE:EXCELLENT': 'Ripe',
 'RASPBERRY:GOOD': 'Ripe'}

This result has been achieved by deploying the following loop method:

fruits_dict = {}

for fruit in fruits_lst:

    if fruit.split(':')[1] != 'Off':

        fruits_dict[fruit.upper()] = 'Ripe'

    else:

        fruits_dict[fruit.lower()] = 'Off'

So this creates a dictionary, but also needs to perform a different function to produce the desired key depending on the fruit.split(':')[1] value.

I have been attempting to re-write this so as to achieve the same result via a comprehension in one line of code, but am still trying to figure out the syntax to deploy to achieve this result.

I have attempted:

{fruit.upper():'Ripe' for fruit in fruits_lst if fruit.split(':') != 'Off' else fruit.lower():'Off'}

{fruit.upper():'Ripe' if fruit.split(':') != 'Off' else fruit.lower():'Off' for fruit in fruits_lst}

however, these all return a SyntaxError.

I note that this produces the dictionary of ripe fruits, but then I am obviously missing the off fruits:

{fruit.upper():'Ripe' for fruit in fruits_lst if fruit.split(':') != 'Off'}

{'APPLE:GOOD': 'Ripe',
 'BANANA:OFF': 'Ripe',
 'BLUEBERRY:EXCELLENT': 'Ripe',
 'ORANGE:EXCELLENT': 'Ripe',
 'RASPBERRY:GOOD': 'Ripe'}

I am looking for the right syntax here, but further to better understand what it is I am missing in how the generation of a dictionary via a comprehension method with an if else condition should be written in this instance.

Thanks!

The question is now updated with more specific detail. Thank you!

CodePudding user response：

One option is to use OR in a generator expression and use the dict constructor:

out = dict((fruit.upper(),'Ripe') * (fruit.split(':')[1]!='Off') or (fruit,'Off') for fruit in fruits_lst)

or simply implement the if-else in a generator expression and construct the dict:

out = dict((fruit.upper(),'Ripe') if fruit.split(':')[1]!='Off' else (fruit,'Off') for fruit in fruits_lst)

Output:

{'APPLE:GOOD': 'Ripe',
 'Banana:Off': 'Off',
 'ORANGE:EXCELLENT': 'Ripe',
 'BLUEBERRY:EXCELLENT': 'Ripe',
 'RASPBERRY:GOOD': 'Ripe'}

CodePudding user response：

Another version:

out = {
    fruit: "Off" if fruit.split(":")[1] == "Off" else "Ripe"
    for fruit in fruits_lst
}

print(out)

Prints:

{
    "Apple:Good": "Ripe",
    "Banana:Off": "Off",
    "Orange:Excellent": "Ripe",
    "Blueberry:Excellent": "Ripe",
    "Raspberry:Good": "Ripe",
}

Or shorter:

out = {
    fruit: "Off" if fruit.endswith(":Off") else "Ripe" for fruit in fruits_lst
}