How can I make my output exclude an element if it equals to zero?

November 23, 2021

So I created this code with the help of Stack Overflow users.

def get_name(string):
    return string.replace("+", "").replace("-", "")

def gnames(input_list: list):
    output = {}
    for entry in input_list:
        if '->' in entry:
            names = entry.split('->')
            output[names[1]] = output[names[0]]
            output[names[0]] = 0
        else:
            name = get_name(entry)
            if name not in output:
                output[name] = 0
            if "++" in entry:
                output[name] += 1
            if "--" in entry:
                output[name] -= 1
    return output
print(gnames(["Jim--", "John--", "Jordan--", "Jim++", "John--", "Jeff--", "June++", "June->Jim"]))

and this returns

{'Jim': 1, 'John': -2, 'Jordan': -1, 'Jeff': -1, 'June': 0}

Now this is right, but I want gnames() to return only the non zero values negative numbers or positive numbers are fine

so in my example, there’s 'June' = 0

and I want the output of gnames() to exclude 'June' = 0 or if any other person has a 0… I want gnames() to exclude it…

so my output in thiscase, should return

{'Jim': 1, 'John': -2, 'Jordan': -1, 'Jeff': -1}

How can I do that??

>Solution :

Also using dictionary comprehension, you can alter your return like so:

return {x:output[x] for x in output if output[x] != 0}

Description of what this does:

# for each element in output
#    if element['name'] != 0 then keep it

Full code:

def get_name(string):
    return string.replace("+", "").replace("-", "")

def gnames(input_list: list):
    output = {}
    for entry in input_list:
        if '->' in entry:
            names = entry.split('->')
            output[names[1]] = output[names[0]]
            output[names[0]] = 0
        else:
            name = get_name(entry)
            if name not in output:
                output[name] = 0
            if "++" in entry:
                output[name] += 1
            if "--" in entry:
                output[name] -= 1
    return {x:output[x] for x in output if output[x] != 0}


print(gnames(["Jim--", "John--", "Jordan--", "Jim++", "John--", "Jeff--", "June++", "June->Jim"]))

# Sample output
# {'Jim': 1, 'John': -2, 'Jordan': -1, 'Jeff': -1}