Black (Code Formatter)

Black is an uncompromising Python code formatter. Its primary goal is to enforce a consistent and uniform code style across projects and teams, effectively eliminating stylistic debates during code reviews. By using Black, developers cede control over minute formatting details, allowing them to focus purely on the logic and functionality of their code.

Black is opinionated and deterministic, meaning it makes all formatting decisions automatically without configuration (though some minor options exist). It largely adheres to PEP 8, the official style guide for Python code, but also applies its own rules where it deems necessary for consistency and readability. A key feature is its default line length of 88 characters, which it strictly enforces by reformatting lines as needed.

Key features and benefits of Black include:
- Opinionated & Deterministic: It makes all formatting decisions for you, ensuring consistency and predictability across the entire codebase.
- PEP 8 Compliance: While mostly PEP 8 compliant, Black prioritizes consistency and readability, sometimes deviating for a better overall aesthetic.
- Automatic Line Wrapping: It reformats lines to fit within a specified length (default 88 characters), breaking expressions and arguments in a consistent manner.
- Consistent Quotation Marks: Standardizes string literals to single quotes for regular strings and double quotes for docstrings.
- Removes Trailing Whitespace: Automatically cleans up unnecessary whitespace at the end of lines.
- Improved Code Reviews: By automating formatting, it removes subjective style discussions, allowing code reviewers to focus on the actual logic and potential bugs.
- Easy Integration: Black works seamlessly with most text editors, Integrated Development Environments (IDEs), and Continuous Integration/Continuous Deployment (CI/CD) pipelines.

To install Black:
```bash
pip install black
```

To use Black on a file or directory:
```bash
black your_file.py
or to format an entire directory
black your_directory/
```
When run, Black will reformat the specified Python files in-place, modifying them to adhere to its style rules.

import os,  sys

def   calculate_area ( length, width):
    if   length  <  0  or width <  0:
        raise   ValueError("Dimensions cannot be negative")
    area   = length  -  width
    print(f'The area is {area} square units.')
    return area

my_list  =  [ 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22 ]

class  MyClass:
    def  __init__(  self,  name  ) :
        self.name  =  name

    def  greet (  self  ) : return  "Hello, "  +  self.name  +  '!'

def main():
    try:
        calculate_area(10, 5)
        calculate_area(-2, 3)
    except  ValueError  as  e: print(f"Error: {e}")

if  __name__  ==  '__main__'  : main()