debugtrace 1.4.0

Output trace logs when debugging Python programs

DebugTrace-py

DebugTrace-py is a library that outputs trace logs when debugging your Python programs. It supports Python 3.7 or later. By embedding "_ = debugtrace.enter()" at the start of the method, you can output the execution status of the program under development.

1. Features

• Automatically outputs the method name, source file name and line number of invokers of debugtrace.enter function.
• Also outputs end logs when the scope ends.
• Indents logs automatically with nested methods and objects.
• Automatically line breaks in value output.
• Uses reflection to output content even for objects of classes that do not implement the __str__ method.
• You can customize output contents by setting debugtrace.ini file.
• You can select sys.stdout, sys.stderr or logging.Logger to output.

2. Install

pip install debugtrace

3. How to use

Do the following for the debug target and related functions and methods:

• Insert "_ = debugtrace.enter()" at the beginning of functions and methods.
• Insert "debugtrace.print('foo', foo)" to output variables to the log if necessary.

The following is an example of a Python program using DebugTrace-py and a log when it is executed.

  # readme_example.py
  import datetime
  import debugtrace

  # Contact class
  class Contact(object):
      def __init__(self, id: int, firstName: str, lastName: str, birthday: datetime.date) -> None:
          _ = debugtrace.enter(self)
          self.id = id
          self.firstName = firstName
          self.lastName  = lastName
          self.birthday  = birthday

  def func2():
      _ = debugtrace.enter()
      contact = [
          Contact(1, 'Akane' , 'Apple', datetime.date(1991, 2, 3)),
          Contact(2, 'Yukari', 'Apple', datetime.date(1992, 3, 4))
      ]
      debugtrace.print('contact', contact)

  def func1():
      _ = debugtrace.enter()
      debugtrace.print('Hello, World!')
      func2()

  func1()

Log output contents:

2024-03-29 18:43:38.112156+0900 DebugTrace-py 1.4.0 on Python 3.12.0
2024-03-29 18:43:38.112209+0900   config file path: <No config file>
2024-03-29 18:43:38.112244+0900   logger: sys.stderr
2024-03-29 18:43:38.112329+0900 
2024-03-29 18:43:38.112367+0900 ______________________________ MainThread #134705475060800 ______________________________
2024-03-29 18:43:38.112384+0900 
2024-03-29 18:43:38.113719+0900 Enter func1 (readme_example.py:22) <- (readme_example.py:26)
2024-03-29 18:43:38.113813+0900 | Hello, World! (readme_example.py:23)
2024-03-29 18:43:38.113907+0900 | Enter func2 (readme_example.py:14) <- (readme_example.py:24)
2024-03-29 18:43:38.114001+0900 | | Enter Contact.__init__ (readme_example.py:7) <- (readme_example.py:16)
2024-03-29 18:43:38.114074+0900 | | Leave Contact.__init__ (readme_example.py:7) duration: 0:00:00.000008
2024-03-29 18:43:38.114166+0900 | | 
2024-03-29 18:43:38.114202+0900 | | Enter Contact.__init__ (readme_example.py:7) <- (readme_example.py:17)
2024-03-29 18:43:38.114240+0900 | | Leave Contact.__init__ (readme_example.py:7) duration: 0:00:00.000007
2024-03-29 18:43:38.114534+0900 | | 
2024-03-29 18:43:38.114574+0900 | | contacts = [
2024-03-29 18:43:38.114596+0900 | |   (__main__.Contact){
2024-03-29 18:43:38.114609+0900 | |     birthday: 1991-02-03, firstName: 'Akane', id: 1, lastName: 'Apple'
2024-03-29 18:43:38.114646+0900 | |   },
2024-03-29 18:43:38.114703+0900 | |   (__main__.Contact){
2024-03-29 18:43:38.114727+0900 | |     birthday: 1992-03-04, firstName: 'Yukari', id: 2, lastName: 'Apple'
2024-03-29 18:43:38.114738+0900 | |   }
2024-03-29 18:43:38.114748+0900 | | ] (readme_example.py:19)
2024-03-29 18:43:38.114778+0900 | | 
2024-03-29 18:43:38.114818+0900 | Leave func2 (readme_example.py:14) duration: 0:00:00.000863
2024-03-29 18:43:38.114859+0900 Leave func1 (readme_example.py:22) duration: 0:00:00.001086

4. Functions

There are mainly the following functions.

Function list

Name	Discription
enter	Outputs an entering log Also outputs a leaving log at the end of the code block. Arguments: invoker (object, optional): Pass the self or cls of the invoker. Examples: _ = debugtrace.enter(self) _ = debugtrace.enter(cls) _ = debugtrace.enter()
print	Outputs the variable name and value Arguments: name (str): Variable name, etc value (object, optional): Value to output (output only name if omitted) The following are keyword arguments force_reflection (bool, optional): If True, outputs using reflection even if it has a __str__ or __repr__ method (default: False) output_private (bool, optional): If True, also outputs private members when using reflection (default: False) output_method (bool, optional): If True, also outputs method members when using reflection (default: False) collection_limit (int, optional): The limit value of elements such as list, tuple and dict to output (default: -1) bytes_limit (int, optional): The limit value of elements for bytes and bytearray to output (default: -1) string_limit (int, optional): The limit value of characters for string to output (default: -1) reflection_nest_limit (int, optional): The The limit value for reflection nesting (default: -1) Examples: debugtrace.print('Hellow') debugtrace.print('foo', foo) debugtrace.print('foo', foo, force_reflection=True) debugtrace.print('foos', foos, collection_limit=1024)

5. Options that can be specified in the debugtrace.ini file

DebugTrace-py reads the debugtrace.ini file in the current directory for initialization. The section is [debugtrace].

You can specify the following options in the debugtrace.ini file.

list

debugtrace.ini

Option Name	Description	Default Value
logger	The logger used by debugtrace Specifiable Values: stdout - Output to sys.stdout stderr - Output to sys.stderr logger - Output using logging package file:< log file path> - Output directly to the file	stderr
logging_config_file	The configuration file name specified in logging package	logging.conf
logging_logger_name	The logger name when using the logging package	debugtrace
is_enabled	Specifiable Values: False: Log output is disabled True: Log output is enabled	True
enter_format	The format string of log output when entering functions or methods {0}: The function or method name {1}: The file name {2}: The line number {3}: The file name of the caller {4}: The line number of the caller	Enter {0} ({1}:{2}) <- ({3}:{4})
leave_format	The format string of log output when leaving functions or methods {0}: The function or method name {1}: The file name {2}: The line number {3}: The time since entered	Leave {0} ({1}:{2}) duration: {3}
thread_boundary_format	The format string of logging at threads boundary {0}: The thread name {1}: The thread ID	______________________________ {0} #{1} ______________________________
maximum_indents	イThe maximum number of indents	32
indent_string	The indentation string for code	\s
data_indent_string	The indentation string for data	\s\s
limit_string	The string to represent that it has exceeded the limit	...
non_output_string (Currently unused)	The string to be output instead of not outputting value	...
cyclic_reference_string	The string to represent that the cyclic reference occurs	*** Cyclic Reference ***
varname_value_separator	The separator string between the variable name and value	\s=\s
key_value_separator	The separator string between the key and value of dictionary and between the attribute name and value	:\s
print_suffix_format	The format string of print method suffix	\s({1}:{2})
count_format	The format string of the number of elements for list, tuple and dict	count:{}
minimum_output_count	The minimum value to output the number of elements for list, tuple and dict	128
length_format	The format string of the length of string and bytes	length:{}
minimum_output_length	The minimum value to output the length of string and bytes	256
log_datetime_format	Log date and time format when logger is StdOut or StdErr	%Y-%m-%d %H:%M:%S.%f%z
maximum_data_output_width	The maximum output width of data	70
bytes_count_in_line	The count in line of bytes	16
collection_limit	The limit value of elements for list, tuple and dict to output	128
bytes_limit	The limit value of elements for bytes and bytearray to output	256
string_limit	The limit value of characters for string to output	256
reflection_nest_limit	The The limit value for reflection nesting	4

Converts \s to space.

6. License

MIT License (MIT)

© 2020 Masato Kokubo

7. Release notes

DebugTrace-py 1.4.0 - March 31, 2024

• print method now returns the value of the argument.
• Changed default values for the following properties.

Property Name	New Default Value	Old Default Value
minimum_output_count	128	16
minimum_output_length	256	16

DebugTrace-py 1.3.0 - March 4, 2023

• Added calling source file name and line number to log output of enter method.
• Abolished logging_level setting in debugtrace.ini and set it to fixed (DEBUG).
• Added log_datetime_format to debugtrace.ini setting item.

DebugTrace-py 1.2.0 - August 15, 2022

• Added the runtime Python version to the startup log.
• Changed to output a log that shows thread switching.
• Changed default values for the following properties.

Property Name	New Default Value	Old Default Value
minimum_output_count	16	5
minimum_output_length	16	5
collection_limit	128	512
bytes_limit	256	8192
string_limit	256	8192

DebugTrace-py 1.1.0 - November 28, 2021

• Fixed a bug that an error occurs when outputting an object of a class that implements __str__ or __repr__.
• Do not output tuple, set, dict data types. (1, 2, 3) ← (tuple)(1, 2, 3)
(1,) ← (tuple)(1)
() ← (tuple)()
{1, 2, 3} ← (set){1, 2, 3}
{} ← (set){}
{1: 'A', 2: 'B', 3; 'C'} ← (dict){1: 'A', 2: 'B', 3; 'C'}
{:} ← (dict){}

DebugTrace-py 1.0.3 - August 12, 2021

• Improved the line break handling of data output

DebugTrace-py 1.0.2 - November 29, 2020

• Change the start message. ('DebugTrace-py ...' <- 'DebugTrace-python ...')

DebugTrace-py 1.0.1 - July 19, 2020

• Improved the line break handling of data output.

DebugTrace-py 1.0.0 - May 26, 2020

• First release