Properties Class

class javaproperties.Properties(data=None, defaults=None)

A port of Java 8’s java.net.Properties that tries to match its behavior as much as is Pythonically possible. Properties behaves like a normal MutableMapping class (i.e., you can do props[key] = value and so forth), except that it may only be used to store strings (str and unicode in Python 2; just str in Python 3). Attempts to use a non-string object as a key or value will produce a TypeError.

Parameters:

• data (mapping or None) – A mapping or iterable of (key, value) pairs with which to initialize the Properties object. All keys and values in data must be text strings.
• defaults (Properties or None) – a set of default properties that will be used as fallback for getProperty

defaults = None

A Properties subobject used as fallback for getProperty. Only getProperty, propertyNames, and stringPropertyNames use this attribute; all other methods (including the standard mapping methods) ignore it.

getProperty(key, defaultValue=None)

Fetch the value associated with the key key in the Properties object. If the key is not present, defaults is checked, and then its defaults, etc., until either a value for key is found or the next defaults is None, in which case defaultValue is returned.

Parameters:

• key (text string) – the key to look up the value of
• defaultValue – the value to return if key is not found in the Properties object

Return type:

text string (if key was found)

Raises:

TypeError – if key is not a string

load(inStream)

Update the Properties object with the entries in a .properties file or file-like object.

inStream may be either a text or binary filehandle, with or without universal newlines enabled. If it is a binary filehandle, its contents are decoded as Latin-1.

Parameters:inStream (file-like object) – the file from which to read the .properties document Returns:None

loadFromXML(inStream)

Update the Properties object with the entries in the XML properties file inStream.

Beyond basic XML well-formedness, loadFromXML only checks that the root element is named properties and that all of its entry children have key attributes; no further validation is performed.

Note

This uses xml.etree.ElementTree for parsing, which does not have decent support for unicode input in Python 2. Files containing non-ASCII characters need to be opened in binary mode in Python 2, while Python 3 accepts both binary and text input.

Parameters:inStream (file-like object) – the file from which to read the XML properties document Returns:None Raises:ValueError – if the root of the XML tree is not a <properties> tag or an <entry> element is missing a key attribute

propertyNames()

Returns a generator of all distinct keys in the Properties object and its defaults (and its defaults’s defaults, etc.) in unspecified order

Return type:generator of text strings

setProperty(key, value)

Equivalent to self[key] = value

store(out, comments=None)

Write the Properties object’s entries (in unspecified order) in .properties format to out, including the current timestamp.

Parameters:

• out – A file-like object to write the properties to. It must have been opened as a text file with a Latin-1-compatible encoding.
• comments (text string or None) – If non-None, comments will be written to out as a comment before any other content

Returns:

None

storeToXML(out, comment=None, encoding='UTF-8')

Write the Properties object’s entries (in unspecified order) in XML properties format to out.

Parameters:

• out (binary file-like object) – a file-like object to write the properties to
• comment (text string or None) – if non-None, comment will be output as a <comment> element before the <entry> elements
• encoding (string) – the name of the encoding to use for the XML document (also included in the XML declaration)

Returns:

None

stringPropertyNames()

Returns a set of all keys in the Properties object and its defaults (and its defaults’s defaults, etc.)

Return type:set of text strings