liteconfig

Lightweight and configurable .ini config parser with dot notation property access.

Features

• dot notation: value = cfg.section.property;

• customizable parsing options;

• no dependencies inside, only plain Python;

• can handle text files, multiline strings or lists as input data;

• no singleton, you can use as much Config objects as you want;

• multiple encodings support, including Unicode;

• read/write config files.

Default parsing options and their meaning

• delimiter = '='
  delimiter between property and value is "=".

• before_delimiter = ' '

• after_delimiter = ' '
  strings which will precede and follow up delimiter character when exporting config to file. For example, property i with value of 0 will be exported as i = 0. And if before_delimiter will be set as :, the same thing will be exported as i := 0.

• comment_markers = '#;'
  empty lines and lines beginning with "#" or ";" are ignored.

• parse_numbers = True
  will try to parse numeric values to int or float.

• parse_booleans = True
  will try to parse boolean values to bool.

• boolean_true = ('yes', 'true', 'on')
  case-insensitive tuple of string values, recognized as boolean "True".

• boolean_false = ('no', 'false', 'off')
  case-insensitive tuple of string values, recognized as boolean "False".

• encoding = 'utf-8'
  parser will try to read and write config files using this encoding.

• exceptions = False
  If True, accessing nonexistent properties (or sections) of config will raise AttributeError. If False, nonexistent property will return None. Absent section will return special object Nothing, which can be tested against truth (and it will always return False). So you can use the construction like

if cfg.section.property:
  # do something with cfg.section.property
else:
  # handle nonexistence

Public methods of Config object

• __init__(input_data [, delimiter, comment_markers, parse_numbers, parse_booleans, boolean_true, boolean_false, encoding, exceptions])
  Instantiates Config object and parses input_data. Depending on type of input_data, instance will parse it as list, as multiline string or will interpret string as path to config file and read it.

• has_section(item)
  Return True or False depending on existence of config section.

• has_property(item [, section])
  Return True or False depending on existence of config property. Will search in all sections by default or in one concrete section if it is passed as second argument.

• write(file)
  Export config to file with the same settings as when object was instantiated.

Error handling

• Attempt to load nonexistent config file will raise FileNotFoundError.

• Also may raise PermissionError if process does not have sufficient privileges to read or write file.

• If desired, access to nonexistent property (or section) will raise AttributeError.

• If input_data is not list nor string nor path to config file, will raise ValueError.

• Fail to decode input_data file will result in UnicodeError.

Notes

• When exporting config, boolean values will always be written like True or False, regardless of initial readings (yes, no, on, off et cetera).

Example

===BEGIN config.ini===
; liteconfig support very simple sectionless configs too
property = value

[section]
; this comment will be ignored
heads=tails
truth = lie
nokia = 3310

[misc]
# this comment will be ignored too
kill_all_humans = yes
pi = 3.14159

[юникод]
文字 = 😉
===END config.ini===

Here we have: comments and empty lines, three sections and one "free" item. Some sections are named using ASCII symbols and one is Unicode. Also notice heads=tails key-value: it isn't necessary to have spaces before and after delimiter. Property and values can also be Unicode: cyrillic, hieroglyphs and emoji are welcome, thanks to Python3.

Default behaviour is to try to represent all numbers as ints and floats, not strings. The same goes to boolean values: notice how yes became True for kill_all_humans property.

import liteconfig

cfg = liteconfig.Config('config.ini')
print(cfg.property)                    # 'value'
print(cfg.section.heads)               # 'tails'
print(cfg.юникод.文字)                 # '😉'

print(cfg.section.nokia)               # 3310
print(type(cfg.section.nokia))         # int

print(cfg.misc.kill_all_humans)        # True
print(type(cfg.misc.kill_all_humans))  # bool

print(cfg.misc.pi)                     # 3.14159
print(type(cfg.misc.pi))               # float
print(cfg.nonexistent)                 # AttributeError exception or None
print(cfg.voidsection.nonexistent)     # AttributeError exception or Nothing (boolean False)
print(cfg.voidsection)                 # AttributeError exception or Nothing (boolean False)

TO-DO

• Parsers for various formats of hierarchical configs (with subsections).

• Support for versions of Python lesser than 3.6 (probably).

History

• 0.0.1: initial release.

• 0.0.2: added option to raise exception or return None/False for absent properties or sections.

• 0.0.3: minor fixes in documentation.

• 0.1.0: added tests. Removed '1' and '0' from parsed booleans, as it conflicts with parsing numbers.

• 0.1.1: minor fixes in documentation.

• 0.1.2: code clean-up.

• 1.0.0: bug-fixing. Tests re-written using pytest. Also, liteconfig learned how to keep comments when writing previously read config.