Today’s discoveries spanned from Python exception handling best practices to Linux system customization and performance optimization.

Python’s raise from Statement

Python’s raise statement with from clause enables proper exception chaining to preserve full tracebacks:

Exception Chaining Fundamentals:

Basic raise from Usage:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19

def process_file(filename):
    try:
        with open(filename, 'r') as f:
            data = json.load(f)
            return data['required_field']
    except FileNotFoundError as e:
        raise ValueError(f"Configuration file {filename} not found") from e
    except KeyError as e:
        raise ValueError(f"Missing required field in {filename}") from e
    except json.JSONDecodeError as e:
        raise ValueError(f"Invalid JSON in {filename}") from e

# Usage example
try:
    config = process_file('config.json')
except ValueError as e:
    print(f"Error: {e}")
    print(f"Original cause: {e.__cause__}")
    print(f"Full traceback includes both exceptions")

Suppressing Exception Context:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13

def clean_error_without_context():
    try:
        risky_operation()
    except InternalError:
        # Suppress the original exception from traceback
        raise UserFriendlyError("Operation failed") from None

def clean_error_with_context():
    try:
        risky_operation()
    except InternalError as e:
        # Preserve original exception for debugging
        raise UserFriendlyError("Operation failed") from e

Advanced Exception Chaining Patterns:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56

import logging
from contextlib import contextmanager

class DatabaseError(Exception):
    """Custom exception with enhanced context"""
    def __init__(self, message, query=None, params=None):
        super().__init__(message)
        self.query = query
        self.params = params

@contextmanager
def database_transaction():
    """Context manager with proper exception handling"""
    connection = None
    try:
        connection = get_database_connection()
        connection.begin()
        yield connection
        connection.commit()
    except DatabaseConnectionError as e:
        if connection:
            connection.rollback()
        raise DatabaseError("Transaction failed - connection issue") from e
    except DatabaseQueryError as e:
        if connection:
            connection.rollback()
        raise DatabaseError(
            "Transaction failed - query error",
            query=e.query,
            params=e.params
        ) from e
    finally:
        if connection:
            connection.close()

# Usage with comprehensive error handling
def update_user_profile(user_id, profile_data):
    try:
        with database_transaction() as db:
            # Multiple operations that might fail
            user = db.get_user(user_id)
            if not user:
                raise UserNotFoundError(f"User {user_id} not found")
            
            validate_profile_data(profile_data)
            db.update_user_profile(user_id, profile_data)
            db.log_user_activity(user_id, "profile_updated")
            
    except UserNotFoundError:
        # Re-raise without chaining - this is the root cause
        raise
    except ValidationError as e:
        raise ProfileUpdateError("Invalid profile data") from e
    except DatabaseError as e:
        logging.error(f"Database error updating user {user_id}: {e.__cause__}")
        raise ProfileUpdateError("Failed to update profile") from e

Exception Chaining Best Practices:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

def api_request_with_retries(url, max_retries=3):
    """Example showing when to chain vs when not to chain"""
    last_exception = None
    
    for attempt in range(max_retries):
        try:
            response = requests.get(url, timeout=10)
            response.raise_for_status()
            return response.json()
            
        except requests.ConnectionError as e:
            last_exception = e
            if attempt == max_retries - 1:
                # Chain the last connection error
                raise APIConnectionError(
                    f"Failed to connect to {url} after {max_retries} attempts"
                ) from e
            time.sleep(2 ** attempt)  # Exponential backoff
            
        except requests.HTTPError as e:
            # Don't retry on HTTP errors - raise immediately with context
            raise APIHttpError(
                f"HTTP {e.response.status_code}: {e.response.reason}"
            ) from e
            
        except requests.Timeout as e:
            last_exception = e
            if attempt == max_retries - 1:
                raise APITimeoutError(
                    f"Request to {url} timed out after {max_retries} attempts"
                ) from e
            time.sleep(1)

Grub Bootloader Customization

Grub Customizer provides a GUI tool for customizing the GRUB bootloader:

Grub Configuration Methods:

Manual Configuration:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13

# Edit GRUB configuration
sudo nano /etc/default/grub

# Common customizations
GRUB_DEFAULT=0                    # Default menu entry
GRUB_TIMEOUT=10                   # Menu timeout in seconds
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"  # Kernel parameters
GRUB_CMDLINE_LINUX=""
GRUB_GFXMODE=1920x1080           # Screen resolution
GRUB_BACKGROUND="/path/to/image.jpg"  # Custom background

# Apply changes
sudo update-grub

Advanced Grub Customization:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21

# Custom menu entries
sudo nano /etc/grub.d/40_custom

# Add custom entry
menuentry "Ubuntu Safe Mode" {
    set root='hd0,gpt2'
    linux /vmlinuz root=/dev/sda2 ro recovery nomodeset
    initrd /initrd.img
}

menuentry "Memory Test" {
    set root='hd0,gpt1'
    linux16 /memtest86+.bin
}

# Custom theme installation
sudo mkdir -p /boot/grub/themes/mytheme
sudo cp -r mytheme/* /boot/grub/themes/mytheme/

# Enable theme in /etc/default/grub
GRUB_THEME="/boot/grub/themes/mytheme/theme.txt"

Grub Rescue Operations:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

# Boot repair from live USB
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt update
sudo apt install boot-repair
sudo boot-repair

# Manual GRUB reinstallation
sudo mount /dev/sda2 /mnt  # Root partition
sudo mount /dev/sda1 /mnt/boot/efi  # EFI partition
sudo grub-install --target=x86_64-efi --efi-directory=/mnt/boot/efi --bootloader-id=ubuntu /dev/sda
sudo update-grub

Liquorix Kernel for Desktop Performance

Liquorix Kernel provides optimized kernel builds for desktop and multimedia workloads:

Liquorix Features:

Performance Optimizations:

  • MuQSS Scheduler: Better interactive performance than CFS
  • Low latency: Optimized for real-time audio/video work
  • Desktop responsiveness: Reduced input lag and smoother UI
  • Gaming optimizations: Better frame time consistency

Installation:

1
2
3
4
5
6
7
8
9

# Add Liquorix repository
curl -s 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x9ae4078033f8024d' | sudo apt-key add -
echo "deb http://liquorix.net/debian sid main" | sudo tee /etc/apt/sources.list.d/liquorix.list

# Install Liquorix kernel
sudo apt update
sudo apt install linux-image-liquorix-amd64 linux-headers-liquorix-amd64

# Reboot and select Liquorix kernel from GRUB menu

Kernel Comparison:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15

# Check current kernel
uname -r

# Compare different kernels
# Standard Ubuntu kernel: 5.4.0-generic
# Liquorix kernel: 5.4-liquorix-amd64
# XanMod kernel: 5.4.0-xanmod1

# Performance testing
# Audio latency test
sudo apt install rt-tests
cyclictest -t1 -p 80 -n -i 500 -l 100000

# System responsiveness
time (dd if=/dev/zero of=/tmp/test bs=1M count=1000; sync)

Phoronix Test Suite - Hardware Benchmarking

Phoronix Test Suite provides comprehensive open-source benchmarking tools:

Benchmarking Capabilities:

Installation and Basic Usage:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

# Install Phoronix Test Suite
sudo apt install phoronix-test-suite

# List available tests
phoronix-test-suite list-available-tests

# System information
phoronix-test-suite system-info

# Hardware detection
phoronix-test-suite detailed-system-info

CPU Benchmarking:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

# CPU-intensive benchmarks
phoronix-test-suite install pts/compress-7zip
phoronix-test-suite run pts/compress-7zip

# Multi-threaded compilation test
phoronix-test-suite install pts/build-linux-kernel
phoronix-test-suite run pts/build-linux-kernel

# Encryption performance
phoronix-test-suite install pts/openssl
phoronix-test-suite run pts/openssl

GPU and Graphics Benchmarking:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

# OpenGL performance
phoronix-test-suite install pts/unigine-valley
phoronix-test-suite run pts/unigine-valley

# Vulkan benchmarks
phoronix-test-suite install pts/vkmark
phoronix-test-suite run pts/vkmark

# GPU compute
phoronix-test-suite install pts/luxcorerender
phoronix-test-suite run pts/luxcorerender

Automated Test Suites:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15

# Comprehensive system test
phoronix-test-suite install pts/desktop
phoronix-test-suite run pts/desktop

# Server benchmarks
phoronix-test-suite install pts/server
phoronix-test-suite run pts/server

# Custom test suite
phoronix-test-suite build-suite

# Batch testing with results upload
phoronix-test-suite batch-setup
phoronix-test-suite batch-run pts/desktop
phoronix-test-suite upload-result

Results Analysis:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

# View test results
phoronix-test-suite list-saved-results
phoronix-test-suite show-result [result-name]

# Compare results
phoronix-test-suite merge-results result1 result2
phoronix-test-suite compare-results-to-baseline result1 baseline

# Generate reports
phoronix-test-suite result-file-to-pdf result1
phoronix-test-suite result-file-to-csv result1

Multiple Kernel Testing:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17

# Automated kernel comparison script
#!/bin/bash
KERNELS=("5.4.0-generic" "5.4-liquorix" "5.4.0-xanmod1")
TESTS=("pts/compress-7zip" "pts/openssl" "pts/build-linux-kernel")

for kernel in "${KERNELS[@]}"; do
    echo "Testing kernel: $kernel"
    # Boot into specific kernel (manual step)
    # Then run benchmarks
    for test in "${TESTS[@]}"; do
        phoronix-test-suite run $test
        mv ~/.phoronix-test-suite/test-results/* "./results-$kernel-$(basename $test)/"
    done
done

# Generate comparison report
phoronix-test-suite merge-results results-*

These tools and techniques provide comprehensive approaches to Python error handling, Linux system customization, and performance analysis - essential skills for effective software development and system administration.