Examples

This page contains the raw code + output of our examples. For detailed explanations of what is going on please see the Quick Start guide.

Example 0 - Most Basic Example

This is the most basic example which demonstrates the most basic way to use LightweightDebugMessages.

Code Listing: Example 0#!/usr/bin/env python3
from lightweightdebugmessages import LightweightDebugMessages



class MyClass(LightweightDebugMessages):

    def some_method(self):
        print("some_method():")
        self.debug_message(0, f"This is a normal message that should always be printed")
        self.debug_message(2, f"This message is printed if debug_level is >= 2")
        self.debug_message(5, f" This message is printed if debug_level is >= 5")
        print("")
        return



# create an instance of the class
data = MyClass()

# Default debug_level is 0, so this prints only 1 message
data.some_method()

# Increase debug level:
data.debug_level = 2
data.some_method()

Output: Example 0

some_method():
This is a normal message that should always be printed

some_method():
This is a normal message that should always be printed
[D-2] This message is printed if debug_level is >= 2

Example 1 - Demonstrate Debug Level Use

Expands Example 0 to show different debug messages being printed.

Code Listing: Example 1#!/usr/bin/env python3
from lightweightdebugmessages import LightweightDebugMessages



class MyClass(LightweightDebugMessages):

    def some_method(self):
        for level in range(10):
            self.debug_message(level, f"This message has debug level {level}")
        return



# create an instance of the class
data = MyClass()

# Demonstrate messages printed with debug_level = 0
print(f"Test method using debug_level = {data.debug_level}:")
data.some_method()
print("")

# Demonstrate messages printed with debug_level = 3
data.debug_level = 3
print(f"Test method using debug_level = {data.debug_level}:")
data.some_method()
print("")

# Demonstrate messages printed with debug_level = 5
data.debug_level = 5
print(f"Test method using debug_level = {data.debug_level}:")
data.some_method()
print("")

Output: Example 1

Test method using debug_level = 0:
This message has debug level 0

Test method using debug_level = 3:
This message has debug level 0
[D-1] This message has debug level 1
[D-2] This message has debug level 2
[D-3] This message has debug level 3

Test method using debug_level = 5:
This message has debug level 0
[D-1] This message has debug level 1
[D-2] This message has debug level 2
[D-3] This message has debug level 3
[D-4] This message has debug level 4
[D-5] This message has debug level 5

Example 2 - Contol Messages via Command Line Argument

Shows a more complex example using argparse to control the visibility of debug messages using the command line by adding the parameter --debug-level=N.

Code Listing: Example 2#!/usr/bin/env python3
import argparse
from lightweightdebugmessages import LightweightDebugMessages



class MyClass(LightweightDebugMessages):

    def __init__(self, program_options):
        self.debug_level = program_options.debug_level

    def some_method(self):
        for level in range(10):
            self.debug_message(level, f"This message has debug level {level}")
        return



def parse_args():
    """
    Parse command line arguments using argparse

    Returns:
        Namespace object containing the command line arguments.
    """

    def int_range(minval=0, maxval=5):
        """ Helper: Sets an allowable range for an int parameter """

        def int_range_checker(arg):
            try:
                output = int(arg)
            except ValueError:
                raise argparse.ArgumentTypeError("Must be an integer value")
            if output < minval:
                output = minval
            if output > maxval:
                output = maxval
            return output

        return int_range_checker

    parser = argparse.ArgumentParser(description='Example')
    required = parser.add_argument_group('Required Arguments')
    optional = parser.add_argument_group('Optional Arguments')

    optional.add_argument(
        "--debug-level",
        dest="debug_level",
        action='store',
        type=int_range(0, 5),
        help='Debug Level [0..5]',
        default=0
    )

    arguments = parser.parse_args()
    return arguments



# Parse the program options
program_options = parse_args()

# create an instance of the class
data = MyClass(program_options)

# Demonstrate messages printed with debug_level = 0
print(f"Test method using debug_level = {data.debug_level}:")
data.some_method()
print("")

Output: Example 1

Test method using debug_level = 0:
This message has debug level 0