Better Division Of Responsibility

Mar 10, 2025 by ADMIN 34 views

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Introduction

In software development, dividing responsibility among classes is crucial for maintaining a clean, scalable, and maintainable codebase. This article discusses the importance of dividing responsibility among classes, specifically in the context of building reports. We will explore how to design a system where each class has a single responsibility, making it easier to modify, extend, or replace individual components without affecting the entire system.

The Problem with Monolithic Classes

In a monolithic class, a single class is responsible for multiple tasks, such as parsing data, building reports, and storing history. This approach can lead to several issues:

Tight Coupling: When a class is responsible for multiple tasks, it becomes tightly coupled to the specific implementation details of each task. This makes it difficult to change or replace one task without affecting the others.
Complexity: A monolithic class can become overly complex, making it harder to understand, maintain, and extend.
Rigidity: When a class is responsible for multiple tasks, it can become rigid and inflexible, making it difficult to adapt to changing requirements.

Designing a Better System

To address the issues mentioned above, we can design a system where each class has a single responsibility. In the context of building reports, we can divide the responsibility among the following classes:

Parser: Responsible for parsing data from various sources, such as CSV, space, or TSV files, or spreadsheets with tabs.
Data Class: Provides column names and rows for the parsed data.
Report Builder: Builds reports based on the data provided by the Data Class.
History Building Class: Provides three different types of reports: 1099 report, everything report, and basic transactions history report.
Raw Transactions Class: Provides fields for raw transactions.

Class Design

Here is an example of how we can design each class:

Parser

The Parser class should be responsible for parsing data from various sources. It can use libraries such as pandas or csv to read data from CSV, space, or TSV files, or spreadsheets with tabs.

import pandas as pd

class Parser:
    def __init__(self, file_path):
        self.file_path = file_path

    def parse_csv(self):
        return pd.read_csv(self.file_path)

    def parse_space(self):
        return pd.read_csv(self.file_path, sep=' ')

    def parse_tsv(self):
        return pd.read_csv(self.file_path, sep='\t')

    def parse_spreadsheet(self):
        return pd.read_excel(self.file_path)

Data Class

The Data Class should provide column names and rows for the parsed data. It can use the pandas library to create a DataFrame.

import pandas as pd

class Data:
    def __init__(self, data):
        self.data = data

    def get_column_names(self):
        return self.data.columns.tolist()

    def get_rows(self):
        return self.data.values.tolist()

Report Builder

The Report Builder class should build reports based on the data provided by the Data Class. It can use the pandas library to create a DataFrame and then use a library such as tabulate to print the report.

import pandas as pd
from tabulate import tabulate

class ReportBuilder:
    def __init__(self, data):
        self.data = data

    def build_report(self):
        return tabulate(self.data, headers='keys', tablefmt='psql')

History Building Class

The History Building Class should provide three different types of reports: 1099 report, everything report, and basic transactions history report. It can use the pandas library to create a DataFrame and then use a library such as tabulate to print the report.

import pandas as pd
from tabulate import tabulate

class HistoryBuilder:
    def __init__(self, data):
        self.data = data

    def build_1099_report(self):
        return tabulate(self.data, headers='keys', tablefmt='psql')

    def build_everything_report(self):
        return tabulate(self.data, headers='keys', tablefmt='psql')

    def build_basic_transactions_history_report(self):
        return tabulate(self.data, headers='keys', tablefmt='psql')

Raw Transactions Class

The Raw Transactions Class should provide fields for raw transactions. It can use the pandas library to create a DataFrame.

import pandas as pd

class RawTransactions:
    def __init__(self, data):
        self.data = data

    def get_fields(self):
        return self.data.columns.tolist()

Conclusion

In conclusion, dividing responsibility among classes is crucial for maintaining a clean, scalable, and maintainable codebase. By designing a system where each class has a single responsibility, we can avoid the issues associated with monolithic classes, such as tight coupling, complexity, and rigidity. The example code provided demonstrates how to design each class and how to use them to build reports.

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Introduction

In our previous article, we discussed the importance of dividing responsibility among classes in software development. We explored how to design a system where each class has a single responsibility, making it easier to modify, extend, or replace individual components without affecting the entire system. In this article, we will answer some frequently asked questions about dividing responsibility among classes.

Q&A

Q: Why is dividing responsibility among classes important?

A: Dividing responsibility among classes is important because it helps to avoid the issues associated with monolithic classes, such as tight coupling, complexity, and rigidity. By giving each class a single responsibility, we can make our code more modular, scalable, and maintainable.

Q: How do I know which classes to divide responsibility among?

A: To determine which classes to divide responsibility among, you should identify the different tasks or functions that your system needs to perform. Then, you can create separate classes for each task or function, making sure that each class has a single responsibility.

Q: What are some common classes that I should divide responsibility among?

A: Some common classes that you should divide responsibility among include:

Parser: Responsible for parsing data from various sources, such as CSV, space, or TSV files, or spreadsheets with tabs.
Data Class: Provides column names and rows for the parsed data.
Report Builder: Builds reports based on the data provided by the Data Class.
History Building Class: Provides three different types of reports: 1099 report, everything report, and basic transactions history report.
Raw Transactions Class: Provides fields for raw transactions.

Q: How do I design each class?

A: To design each class, you should follow these steps:

Identify the responsibility: Determine what task or function each class will be responsible for.
Create a class: Create a new class with a name that reflects its responsibility.
Add methods: Add methods to the class that will perform the necessary tasks or functions.
Use libraries: Use libraries such as pandas or csv to read data from CSV, space, or TSV files, or spreadsheets with tabs.
Test the class: Test the class to ensure that it is working correctly.

Q: What are some benefits of dividing responsibility among classes?

A: Some benefits of dividing responsibility among classes include:

Modularity: Dividing responsibility among classes makes our code more modular, making it easier to modify, extend, or replace individual components without affecting the entire system.
Scalability: Dividing responsibility among classes makes our code more scalable, making it easier to add new features or functions without affecting the entire system.
Maintainability: Dividing responsibility among classes makes our code more maintainable, making it easier to fix bugs or make changes without affecting the entire system.

Q: What are some common mistakes to avoid when dividing responsibility among classes?

A: Some common mistakes to avoid when dividing responsibility among classes include:

Tight coupling: Avoid making classes tightly coupled by ensuring that each class has a single responsibility.
Complexity: Avoid making classes too complex by breaking down large tasks into smaller, more manageable tasks.
Rigidity: Avoid making classes too rigid by ensuring that each class can be modified or extended without affecting the entire system.

Conclusion

In conclusion, dividing responsibility among classes is an important aspect of software development. By following the steps outlined in this article, you can design a system where each class has a single responsibility, making it easier to modify, extend, or replace individual components without affecting the entire system. Remember to avoid common mistakes such as tight coupling, complexity, and rigidity, and to test your classes to ensure that they are working correctly.