Preferences 0.08

It a simple class that creates a list of dictionarries to store preferences as key value pairs. You can use the class directly or load the preferences from files. The main reason I wrote it was to create an easy way of storing more than one preference with the same name and load them form files in a manner that allows for easy appending or replacing of parmeters that could have been loaded from a default prameter file. There are also several methods to make managing the preferences easier.

Help on module Preferences:

NAME

Preferences

FILE

/home/nosrednakram/work/preferences/src/Preferences/Preferences.py

CLASSES

Preferences

class Preferences

Preference CLASS

It a simple class that creates a list of dictionarries to store

preferences as key value pairs for managing parameter sets. You

can use the class directly or load the parameters from files.

The main reason I wrote it was so that I could have an easy way

of storing more than one preference with the same name and load

them form files in a manner that allows for easy appending or

replacing of parmeters that could have been loaded from a

default prameter file.

Config Files:

The load_files will try to read files from three locations

by default: /etc/file, ~/.file, cwd/.file and load them in

that order but you can always pass in a list of files to

load. load_files uses read_file so you can use it to load

files one at a time if you would prefer.

Here are a few examples.

/etc/my_prefs

Organization: NosrednaKram.com

[User Home]/.my_prefs

Author: Mark Anderson

Maintainer: Mark Anderson

Email: Nosrednakram < at > GMail < dot > Com

[CWD]/.my_prefs

Project= Nosrednakram Preferences

Description= You can do multi-line

Just start lines with four spaces

and they will be appended regardless

of formating

Author: Someone Else

Author: Yet again Somone Else

The file content should begin in postion 1 of the file unless

it’s a continuation then it should start with four spaces then

the content.

The : seperator allows for more than one paramter with that

name.

The = Seperator will remove all previous loaded parameters

with the same name and then add. It will just add if no

previous parameters were set. Basiclly use for a preference

when you only want one returned.

Code Examples: (Assuming at least one file exists)

# Import

from Preferences import Preferences

# Create Preferences instance

project = Preferences()

# Load Preferences for dfault locations if they exist

project.load_files(‘my_prefs’)

# List the Authors with a loop

for author in project.get(‘Author’):

print(‘Author: %s’ % author

# Print Authors as a CSV

print project.get_csv(‘Author’)

# Add and additional Author

project.add({‘Author’: ‘Yet Another Person’})

# Add more preferences from another file

project.read_file(‘additional_file.prf’)

# Dump the project preferences to standard out

project.dump()

# see test.py for more usage examples.

Methods defined here:

__init__(self, param=None)

add(self, pref=None)

Append a parameter to the params list.

dump(self)

I use this for debugging some times.

get(self, pref)

get(self, pref)

Looks up all preferences of the provieded type.

Returns ‘’ if no parameters were found.

Returns value if only one parameter was found

Returns list of values if more than one parameter was found.

get_csv(self, pref)

This return a csv list of the specified preference values or

‘’ if there are not matching preferences.

has(self, pref, value)

When passed a parameter and value it returns true if a matching

key value pair exists and False otherwise.

has_pref(self, pref)

Returns True if a parameter with that name exists and fails

otherwise.

load_files(self, file_name, path=[])

When called with a path that is a list of paths to configuration

files they are read in the order they appear in the list. If not

it will first look for files in /etc, the users home directory, and

then the current working director for the passed in file name. The

exception is a . is prepended to the file name in the users

directory. These files are all loaded so you can define global,

local and user preferences. See read_file for more on thy syntax.

read_file(self, file)

Reads preferences from a file line by line. Skipping all lines

beginning with a # or newline. splitting on the first =, * or :.

If split on an = other parameters with the same name are removed

then the preference is added irregardless of if there were

pre-exising preferences with the same name.

If split on an * the preference is simply added allowing for the

same preference to appear several times even with the same value.

If split on an : the key value pair is forced to be unique and if

there are multipul key value pairs that match all but one set is

removed.

It will raise a Value error and provide the line number the error

appeard on if there is an line within your preferences file it

doesn’t know how to handle.

replace_key(self, pref, new_value)

First all occurances of the preference are removed. Then the

parameter is added regardless of weather or not an existing

parameter was found. See add for more details

uniq_key_value(self, pref, value)

If you need unique key value pairs. For example if you have a

parameter that my appear in more than one config file but you

only want one occurance reported. Like ~./prefs has author mark

and .cwd also has author mark you would only return one author

mark but you could have another author that would also get returned.

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Data and other attributes defined here:

params = []