I need help with Budget App: create_spend_chart

[Orses]

Sorry to ask for help on this topic that has already appeared on the forum before. But I am not able to take advantage of other people’s solutions to solve my case.
In principle, the function prints everything fine and 403 characters. But I can’t pass the test, and I’m not able to know why.
Thanks in advance
Greetings

def create_spend_chart(categories):
    num_categories = len(categories)
    total_expenses = 0
    resume_categories = []
    num_characters = 0

    # collecting data
    for category in categories:
        expenses = 0
        for note in category.ledger:
            if note['amount'] < 0:
                expenses += abs(note['amount'])
                total_expenses += expenses

        resume_categories.append({'name': category.name, 'expenses': expenses})
        num_characters = max(num_characters, len(category.name))

    # printing information
    groups = 11  # y axis for scale
    pad = 4
    letter_index = 0
    lines = ['Percentage spent by category']

    for line in range(12 + num_characters):
        if line < groups:
            partial = [f'{100 - line * 10}|'.rjust(pad, " ")]
            for category in resume_categories:
                category['%expenses'] = round_down(
                    category['expenses'] / total_expenses * 100, -1)
                if (100 - line * 10) <= category['%expenses']:
                    partial.append('o ')
                else:
                    partial.append('  ')
            lines.append(' '.join(partial) + ' ')

        if line == groups:
            lines.append(" " * pad + "-" * (num_categories * 2 + 4))
        if line > groups:
            partial = [" " * pad]
            for category in resume_categories:
                if letter_index < len(category['name']):
                    partial.append(category['name'][letter_index] + ' ')
                else:
                    partial.append('  ')
            lines.append(' '.join(partial) + ' ')
            letter_index += 1

    print('\n'.join(lines))

def round_down(number, num_decimals=0):
    multiplier = 10 ** num_decimals
    return math.floor(number * multiplier) / multiplier
```![budget-app|276x474](upload://6peT4Iud0w4VWi7XEGprENakN2D.png)

[sanity]

Could you show also your implementation of the Category class? Having all of the code it will be easier to help.

[Orses]

Without a doubt, thanks for your interest.

import math


class Category:
    def __init__(self, name):
        self.name = name
        self.ledger = []

    def deposit(self, amount, description=''):
        self.ledger.append({'amount': amount, 'description': description})

    def withdraw(self, amount, description=''):
        if self.check_funds(amount):
            self.ledger.append({'amount': -amount, 'description': description})
            return True
        return False

    def get_balance(self):
        balance = sum([note['amount'] for note in self.ledger])
        return balance

    def transfer(self, amount, category):
        if self.check_funds(amount):
            self.withdraw(amount, f'Transfer to {category.name}')
            category.deposit(amount, f'Transfer from {self.name}')
            return True
        return False

    def check_funds(self, amount):
        return amount <= self.get_balance()

    def __str__(self):
        total_characterers = 30
        total_amount = 0
        pad = total_characterers // 2 - len(self.name) // 2
        lines = ''
        lines += f'{"*" * pad}{self.name}{"*" * pad}'
        for note in self.ledger:
            total_amount += note['amount']
            amount_format = f'{note["amount"]:0.02f}'
            lines += f'\n{note["description"][:23].ljust(23)}{amount_format.rjust(7)}'
        lines += f'\nTotal: {total_amount:0.02f}'
        return lines


def create_spend_chart(categories):
    num_categories = len(categories)
    total_expenses = 0
    resume_categories = []
    num_characters = 0

    # collecting data
    for category in categories:
        expenses = 0
        for note in category.ledger:
            if note['amount'] < 0:
                expenses += abs(note['amount'])
                total_expenses += expenses

        resume_categories.append({'name': category.name, 'expenses': expenses})
        num_characters = max(num_characters, len(category.name))

    # printing information
    groups = 11  # y axis for scale
    pad = 4
    letter_index = 0
    lines = ['Percentage spent by category']

    for line in range(groups + 1 + num_characters):
        if line < groups:
            partial = [f'{100 - line * 10}|'.rjust(pad, " ")]
            for category in resume_categories:
                category['%expenses'] = round_down(
                    category['expenses'] / total_expenses * 100, -1)
                if (100 - line * 10) <= category['%expenses']:
                    partial.append('o ')
                else:
                    partial.append('  ')
            lines.append(' '.join(partial) + ' ')

        if line == groups:
            lines.append(" " * pad + "-" * (num_categories * 2 + 4))
        if line > groups:
            partial = [" " * pad]
            for category in resume_categories:
                if letter_index < len(category['name']):
                    partial.append(category['name'][letter_index] + ' ')
                else:
                    partial.append('  ')
            lines.append(' '.join(partial) + ' ')
            letter_index += 1

    print('\n'.join(lines))

def round_down(number, num_decimals=0):
    multiplier = 10 ** num_decimals
    return math.floor(number * multiplier) / multiplier

[sanity]

Function is expected to return the string with the chart, per specification, it doesn’t need nor should print it on it own.

[Orses]

Wow, I feel embarrassed.
It has worked as you tell me.
Thank you very much for your help!
I’ve been thinking about it all afternoon.
Thanks!

[sanity]

Failing test was writing that in it own - a bit convoluted way, it can be hard sometimes to figure out what it’s trying to say exactly.

You might have noticed, in the output, somewhere above what is on the image, printed None. That was actually what function was returning at the time. When function isn’t returning anything explicitly, python returns None.

[Orses]

You are right, I have replicated the problem and see in the error message “AssertionError: None !=…”
Now, I understand the message of the test.