javaproperties — Read & write Java .properties files in Python

GitHub | PyPI | Documentation | Issues | Changelog

Simple Line-Oriented .properties Format

Format Overview

The simple line-oriented .properties file format consists of a series of key-value string pairs, one (or fewer) per line, with the key & value separated by the first occurrence of an equals sign (=, optionally with surrounding whitespace), a colon (:, optionally with surrounding whitespace), or non-leading whitespace. A line without a separator is treated as a key whose value is the empty string. If the same key occurs more than once in a single file, only its last value is used.

Note

Lines are terminated by \n (LF), \r\n (CR LF), or \r (CR).

Note

For the purposes of this format, only the space character (ASCII 0x20), the tab character (ASCII 0x09), and the form feed character (ASCII 0x0C) count as whitespace.

Leading whitespace on a line is ignored, but trailing whitespace (after stripping trailing newlines) is not. Lines whose first non-whitespace character is # or ! (not escaped) are comments and are ignored.

Entries can be extended across multiple lines by ending all but the last line with a backslash; the backslash, the line ending after it, and any leading whitespace on the next line will all be discarded. A backslash at the end of a comment line has no effect. A comment line after a line that ends with a backslash is treated as part of a normal key-value entry, not as a comment.

Occurrences of =, :, #, !, and whitespace inside a key or value are escaped with a backslash. In addition, the following escape sequences are recognized:

\t \n \f \r \uXXXX \\

Unicode characters outside the Basic Multilingual Plane can be represented by a pair of \uXXXX escape sequences encoding the corresponding UTF-16 surrogate pair.

If a backslash is followed by character other than those listed above, the backslash is discarded.

An example simple line-oriented .properties file:

#This is a comment.
foo=bar
baz: quux
gnusto cleesh
snowman = \u2603
goat = \ud83d\udc10
novalue
host\:port=127.0.0.1\:80

This corresponds to the Python dict:

{
    "foo": "bar",
    "baz": "quux",
    "gnusto": "cleesh",
    "snowman": "☃",
    "goat": "🐐",
    "novalue": "",
    "host:port": "127.0.0.1:80",
}

File Encoding

Although the load() and loads() functions accept arbitrary Unicode characters in their input, by default the dump() and dumps() functions limit the characters in their output as follows:

  • When ensure_ascii is True (the default), dump() and dumps() output keys & values in pure ASCII; non-ASCII and unprintable characters are escaped with the escape sequences listed above. When ensure_ascii is False, the functions instead pass all non-ASCII characters through as-is; unprintable characters are still escaped.

  • When ensure_ascii_comments is None (the default), dump() and dumps() output the comments argument (if set) using only Latin-1 (ISO-8859-1) characters; all other characters are escaped. When ensure_ascii_comments is True, the functions instead escape all non-ASCII characters in comments. When ensure_ascii_comments is False, the functions instead pass all characters in comments through as-is.

    • Note that, in order to match the behavior of Java’s Properties class, unprintable ASCII characters in comments are always passed through as-is rather than escaped.

    • Newlines inside comments are not escaped, but a # is inserted after every one not already followed by a # or !.

When writing properties to a file, you must either (a) open the file using an encoding that supports all of the characters in the formatted output or else (b) open the file using the ‘javapropertiesreplace’ error handler defined by this module. The latter option allows one to write valid simple-format properties files in any encoding without having to worry about whether the properties or comment contain any characters not representable in the encoding.

Functions

javaproperties.dump(props: Mapping[str, str] | Iterable[tuple[str, str]], fp: TextIO, separator: str = '=', comments: str | None = None, timestamp: None | bool | float | datetime = True, sort_keys: bool = False, ensure_ascii: bool = True, ensure_ascii_comments: bool | None = None) → None[source]

Write a series of key-value pairs to a file in simple line-oriented .properties format.

Changed in version 0.6.0: ensure_ascii and ensure_ascii_comments parameters added

Parameters:

  • props – A mapping or iterable of (key, value) pairs to write to fp. All keys and values in props must be str values. If sort_keys is False, the entries are output in iteration order.

  • fp (TextIO) – A file-like object to write the values of props to. It must have been opened as a text file.

  • separator (str) – The string to use for separating keys & values. Only " ", "=", and ":" (possibly with added whitespace) should ever be used as the separator.

  • comments (Optional[str]) – if non-None, comments will be written to fp as a comment before any other content

  • timestamp (None, bool, number, or datetime.datetime) – If neither None nor False, a timestamp in the form of Mon Sep 02 14:00:54 EDT 2016 is written as a comment to fp after comments (if any) and before the key-value pairs. If timestamp is True, the current date & time is used. If it is a number, it is converted from seconds since the epoch to local time. If it is a datetime.datetime object, its value is used directly, with naïve objects assumed to be in the local timezone.

  • sort_keys (bool) – if true, the elements of props are sorted lexicographically by key in the output

  • ensure_ascii (bool) – if true, all non-ASCII characters will be replaced with \uXXXX escape sequences in the output; if false, non-ASCII characters will be passed through as-is

  • ensure_ascii_comments (Optional[bool]) – if true, all non-ASCII characters in comments will be replaced with \uXXXX escape sequences in the output; if None, only non-Latin-1 characters will be escaped; if false, no characters will be escaped

Returns:

None

javaproperties.dumps(props: Mapping[str, str] | Iterable[tuple[str, str]], separator: str = '=', comments: str | None = None, timestamp: None | bool | float | datetime = True, sort_keys: bool = False, ensure_ascii: bool = True, ensure_ascii_comments: bool | None = None) → str[source]

Convert a series of key-value pairs to a str in simple line-oriented .properties format.

Changed in version 0.6.0: ensure_ascii and ensure_ascii_comments parameters added

Parameters:

  • props – A mapping or iterable of (key, value) pairs to serialize. All keys and values in props must be str values. If sort_keys is False, the entries are output in iteration order.

  • separator (str) – The string to use for separating keys & values. Only " ", "=", and ":" (possibly with added whitespace) should ever be used as the separator.

  • comments (Optional[str]) – if non-None, comments will be output as a comment before any other content

  • timestamp (None, bool, number, or datetime.datetime) – If neither None nor False, a timestamp in the form of Mon Sep 02 14:00:54 EDT 2016 is output as a comment after comments (if any) and before the key-value pairs. If timestamp is True, the current date & time is used. If it is a number, it is converted from seconds since the epoch to local time. If it is a datetime.datetime object, its value is used directly, with naïve objects assumed to be in the local timezone.

  • sort_keys (bool) – if true, the elements of props are sorted lexicographically by key in the output

  • ensure_ascii (bool) – if true, all non-ASCII characters will be replaced with \uXXXX escape sequences in the output; if false, non-ASCII characters will be passed through as-is

  • ensure_ascii_comments (Optional[bool]) – if true, all non-ASCII characters in comments will be replaced with \uXXXX escape sequences in the output; if None, only non-Latin-1 characters will be escaped; if false, no characters will be escaped

Return type:

text string

javaproperties.load(fp: IO) → dict[str, str][source]
javaproperties.load(fp: IO, object_pairs_hook: type[T]) → T
javaproperties.load(fp: IO, object_pairs_hook: Callable[[Iterator[tuple[str, str]]], T]) → T

Parse the contents of the readline-supporting file-like object fp as a simple line-oriented .properties file and return a dict of the key-value pairs.

fp 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.

By default, the key-value pairs extracted from fp are combined into a dict with later occurrences of a key overriding previous occurrences of the same key. To change this behavior, pass a callable as the object_pairs_hook argument; it will be called with one argument, a generator of (key, value) pairs representing the key-value entries in fp (including duplicates) in order of occurrence. load will then return the value returned by object_pairs_hook.

Changed in version 0.5.0: Invalid \uXXXX escape sequences will now cause an InvalidUEscapeError to be raised

Parameters:

  • fp (IO) – the file from which to read the .properties document

  • object_pairs_hook (callable) – class or function for combining the key-value pairs

Return type:

dict of text strings or the return value of object_pairs_hook

Raises:

InvalidUEscapeError – if an invalid \uXXXX escape sequence occurs in the input

javaproperties.loads(s: str | bytes) → dict[str, str][source]
javaproperties.loads(s: str | bytes, object_pairs_hook: type[T]) → T
javaproperties.loads(s: str | bytes, object_pairs_hook: Callable[[Iterator[tuple[str, str]]], T]) → T

Parse the contents of the string s as a simple line-oriented .properties file and return a dict of the key-value pairs.

s may be either a text string or bytes string. If it is a bytes string, its contents are decoded as Latin-1.

By default, the key-value pairs extracted from s are combined into a dict with later occurrences of a key overriding previous occurrences of the same key. To change this behavior, pass a callable as the object_pairs_hook argument; it will be called with one argument, a generator of (key, value) pairs representing the key-value entries in s (including duplicates) in order of occurrence. loads will then return the value returned by object_pairs_hook.

Changed in version 0.5.0: Invalid \uXXXX escape sequences will now cause an InvalidUEscapeError to be raised

Parameters:

  • s (Union[str,bytes]) – the string from which to read the .properties document

  • object_pairs_hook (callable) – class or function for combining the key-value pairs

Return type:

dict of text strings or the return value of object_pairs_hook

Raises:

InvalidUEscapeError – if an invalid \uXXXX escape sequence occurs in the input

XML .properties Format

Format Overview

The XML .properties file format encodes a series of key-value string pairs (and optionally also a comment) as an XML document conforming to the following Document Type Definition (published at <http://java.sun.com/dtd/properties.dtd>):

<!ELEMENT properties (comment?, entry*)>
<!ATTLIST properties version CDATA #FIXED "1.0">
<!ELEMENT comment (#PCDATA)>
<!ELEMENT entry (#PCDATA)>
<!ATTLIST entry key CDATA #REQUIRED>

An example XML .properties file:

<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
<comment>This is a comment.</comment>
<entry key="foo">bar</entry>
<entry key="snowman">☃</entry>
<entry key="goat">🐐</entry>
<entry key="host:port">127.0.0.1:80</entry>
</properties>

This corresponds to the Python dict:

{
    "foo": "bar",
    "snowman": "☃",
    "goat": "🐐",
    "host:port": "127.0.0.1:80",
}

Functions

javaproperties.dump_xml(props: Mapping[str, str] | Iterable[tuple[str, str]], fp: BinaryIO, comment: str | None = None, encoding: str = 'UTF-8', sort_keys: bool = False) → None[source]

Write a series props of key-value pairs to a binary filehandle fp in the format of an XML properties file. The file will include both an XML declaration and a doctype declaration.

Parameters:

  • props – A mapping or iterable of (key, value) pairs to write to fp. All keys and values in props must be str values. If sort_keys is False, the entries are output in iteration order.

  • fp (BinaryIO) – a file-like object to write the values of props to

  • comment (Optional[str]) – if non-None, comment will be output as a <comment> element before the <entry> elements

  • encoding (str) – the name of the encoding to use for the XML document (also included in the XML declaration)

  • sort_keys (bool) – if true, the elements of props are sorted lexicographically by key in the output

Returns:

None

javaproperties.dumps_xml(props: Mapping[str, str] | Iterable[tuple[str, str]], comment: str | None = None, sort_keys: bool = False) → str[source]

Convert a series props of key-value pairs to a str containing an XML properties document. The document will include a doctype declaration but not an XML declaration.

Parameters:

  • props – A mapping or iterable of (key, value) pairs to serialize. All keys and values in props must be str values. If sort_keys is False, the entries are output in iteration order.

  • comment (Optional[str]) – if non-None, comment will be output as a <comment> element before the <entry> elements

  • sort_keys (bool) – if true, the elements of props are sorted lexicographically by key in the output

Return type:

str

javaproperties.load_xml(fp: IO) → dict[str, str][source]
javaproperties.load_xml(fp: IO, object_pairs_hook: type[T]) → T
javaproperties.load_xml(fp: IO, object_pairs_hook: Callable[[Iterator[tuple[str, str]]], T]) → T

Parse the contents of the file-like object fp as an XML properties file and return a dict of the key-value pairs.

Beyond basic XML well-formedness, load_xml only checks that the root element is named “properties” and that all of its <entry> children have key attributes. No further validation is performed; if any <entry>s happen to contain nested tags, the behavior is undefined.

By default, the key-value pairs extracted from fp are combined into a dict with later occurrences of a key overriding previous occurrences of the same key. To change this behavior, pass a callable as the object_pairs_hook argument; it will be called with one argument, a generator of (key, value) pairs representing the key-value entries in fp (including duplicates) in order of occurrence. load_xml will then return the value returned by object_pairs_hook.

Parameters:

  • fp (IO) – the file from which to read the XML properties document

  • object_pairs_hook (callable) – class or function for combining the key-value pairs

Return type:

dict or the return value of object_pairs_hook

Raises:

ValueError – if the root of the XML tree is not a <properties> tag or an <entry> element is missing a key attribute

javaproperties.loads_xml(s: AnyStr) → dict[str, str][source]
javaproperties.loads_xml(fp: IO, object_pairs_hook: type[T]) → T
javaproperties.loads_xml(s: AnyStr, object_pairs_hook: Callable[[Iterator[tuple[str, str]]], T]) → T

Parse the contents of the string s as an XML properties document and return a dict of the key-value pairs.

Beyond basic XML well-formedness, loads_xml only checks that the root element is named “properties” and that all of its <entry> children have key attributes. No further validation is performed; if any <entry>s happen to contain nested tags, the behavior is undefined.

By default, the key-value pairs extracted from s are combined into a dict with later occurrences of a key overriding previous occurrences of the same key. To change this behavior, pass a callable as the object_pairs_hook argument; it will be called with one argument, a generator of (key, value) pairs representing the key-value entries in s (including duplicates) in order of occurrence. loads_xml will then return the value returned by object_pairs_hook.

Parameters:

  • s (Union[str,bytes]) – the string from which to read the XML properties document

  • object_pairs_hook (callable) – class or function for combining the key-value pairs

Return type:

dict or the return value of object_pairs_hook

Raises:

ValueError – if the root of the XML tree is not a <properties> tag or an <entry> element is missing a key attribute

Properties Class

class javaproperties.Properties(data: None | Mapping[str, str] | Iterable[tuple[str, str]] = None, defaults: Properties | None = None)[source]

A port of Java 8’s java.util.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 str values.

Two Properties instances compare equal iff both their key-value pairs and defaults attributes are equal. When comparing a Properties instance to any other type of mapping, only the key-value pairs are considered.

Changed in version 0.5.0: Properties instances can now compare equal to dicts and other mapping types

Parameters:

  • data (mapping or None) – A mapping or iterable of (key, value) pairs with which to initialize the Properties instance. All keys and values in data must be text strings.

  • defaults (Optional[Properties]) – a set of default properties that will be used as fallback for getProperty

copy() → Properties[source]

Added in version 0.5.0.

Create a shallow copy of the mapping. The copy’s defaults attribute will be the same instance as the original’s defaults.

defaults

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

getProperty(key: str, defaultValue: T | None = None) → str | T | None[source]

Fetch the value associated with the key key in the Properties instance. 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 (str) – the key to look up the value of

  • defaultValue (Any) – the value to return if key is not found in the Properties instance

Return type:

str (if key was found)

load(inStream: IO) → None[source]

Update the Properties instance 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.

Changed in version 0.5.0: Invalid \uXXXX escape sequences will now cause an InvalidUEscapeError to be raised

Parameters:

inStream (IO) – the file from which to read the .properties document

Returns:

None

Raises:

InvalidUEscapeError – if an invalid \uXXXX escape sequence occurs in the input

loadFromXML(inStream: IO) → None[source]

Update the Properties instance 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.

Parameters:

inStream (IO) – 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() → Iterator[str][source]

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

Return type:

Iterator[str]

setProperty(key: str, value: str) → None[source]

Equivalent to self[key] = value

store(out: TextIO, comments: str | None = None) → None[source]

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

Parameters:

  • out (TextIO) – 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 (Optional[str]) – If non-None, comments will be written to out as a comment before any other content

Returns:

None

storeToXML(out: BinaryIO, comment: str | None = None, encoding: str = 'UTF-8') → None[source]

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

Parameters:

  • out (BinaryIO) – a file-like object to write the properties to

  • comment (Optional[str]) – if non-None, comment will be output as a <comment> element before the <entry> elements

  • encoding (str) – the name of the encoding to use for the XML document (also included in the XML declaration)

Returns:

None

stringPropertyNames() → set[str][source]

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

Return type:

set[str]

PropertiesFile Class

class javaproperties.PropertiesFile(mapping: None | Mapping[str, str] | Iterable[tuple[str, str]] = None, **kwargs: str)[source]

Added in version 0.3.0.

A custom mapping class for reading from, editing, and writing to a .properties file while preserving comments & whitespace in the original input.

A PropertiesFile instance can be constructed from another mapping and/or iterable of pairs, after which it will act like an OrderedDict. Alternatively, an instance can be constructed from a file or string with PropertiesFile.load() or PropertiesFile.loads(), and the resulting instance will remember the formatting of its input and retain that formatting when written back to a file or string with the dump() or dumps() method. The formatting information attached to an instance pf can be forgotten by constructing another mapping from it via dict(pf), OrderedDict(pf), or even PropertiesFile(pf) (Use the copy() method if you want to create another PropertiesFile instance with the same data & formatting).

When not reading or writing, PropertiesFile behaves like a normal MutableMapping class (i.e., you can do props[key] = value and so forth), except that (a) like OrderedDict, key insertion order is remembered and is used when iterating & dumping (and reversed is supported), and (b) like Properties, it may only be used to store strings and will raise a TypeError if passed a non-string object as key or value.

Two PropertiesFile instances compare equal iff both their key-value pairs and comment & whitespace lines are equal and in the same order. When comparing a PropertiesFile to any other type of mapping, only the key-value pairs are considered, and order is ignored.

PropertiesFile currently only supports reading & writing the simple line-oriented format, not XML.

copy() → PropertiesFile[source]

Create a copy of the mapping, including formatting information

dump(fp: TextIO, separator: str = '=', ensure_ascii: bool = True) → None[source]

Write the mapping to a file in simple line-oriented .properties format.

If the instance was originally created from a file or string with PropertiesFile.load() or PropertiesFile.loads(), then the output will include the comments and whitespace from the original input, and any keys that haven’t been deleted or reassigned will retain their original formatting and multiplicity. Key-value pairs that have been modified or added to the mapping will be reformatted with join_key_value() using the given separator and ensure_ascii setting. All key-value pairs are output in the order they were defined, with new keys added to the end.

Changed in version 0.8.0: ensure_ascii parameter added

Note

Serializing a PropertiesFile instance with the dump() function instead will cause all formatting information to be ignored, as dump() will treat the instance like a normal mapping.

Parameters:

  • fp (TextIO) – A file-like object to write the mapping to. It must have been opened as a text file with a Latin-1-compatible encoding.

  • separator (str) – The string to use for separating new or modified keys & values. Only " ", "=", and ":" (possibly with added whitespace) should ever be used as the separator.

  • ensure_ascii (bool) – if true, all non-ASCII characters in new or modified key-value pairs will be replaced with \uXXXX escape sequences in the output; if false, non-ASCII characters will be passed through as-is

Returns:

None

dumps(separator: str = '=', ensure_ascii: bool = True) → str[source]

Convert the mapping to a str in simple line-oriented .properties format.

If the instance was originally created from a file or string with PropertiesFile.load() or PropertiesFile.loads(), then the output will include the comments and whitespace from the original input, and any keys that haven’t been deleted or reassigned will retain their original formatting and multiplicity. Key-value pairs that have been modified or added to the mapping will be reformatted with join_key_value() using the given separator and ensure_ascii setting. All key-value pairs are output in the order they were defined, with new keys added to the end.

Changed in version 0.8.0: ensure_ascii parameter added

Note

Serializing a PropertiesFile instance with the dumps() function instead will cause all formatting information to be ignored, as dumps() will treat the instance like a normal mapping.

Parameters:

  • separator (str) – The string to use for separating new or modified keys & values. Only " ", "=", and ":" (possibly with added whitespace) should ever be used as the separator.

  • ensure_ascii (bool) – if true, all non-ASCII characters in new or modified key-value pairs will be replaced with \uXXXX escape sequences in the output; if false, non-ASCII characters will be passed through as-is

Return type:

str

property header_comment: str | None

Added in version 0.7.0.

The concatenated values of all comments at the top of the file, up to (but not including) the first key-value pair or timestamp comment, whichever comes first. The comments are returned with comment markers and the whitespace leading up to them removed, with line endings changed to \n, and with the line ending on the final comment (if any) removed. Blank/all-whitespace lines among the comments are ignored.

The header comment can be changed by assigning to this property. Assigning a string s causes everything before the first key-value pair or timestamp comment to be replaced by the output of to_comment(s). Assigning None causes the header comment to be deleted (also achievable with del pf.header_comment).

>>> pf = PropertiesFile.loads('''\
... #This is a comment.
...   ! This is also a comment.
... #Tue Feb 25 19:13:27 EST 2020
... key = value
... zebra: apple
... ''')
>>> pf.header_comment
'This is a comment.\n This is also a comment.'
>>> pf.header_comment = 'New comment'
>>> print(pf.dumps(), end='')
#New comment
#Tue Feb 25 19:13:27 EST 2020
key = value
zebra: apple
>>> del pf.header_comment
>>> pf.header_comment is None
True
>>> print(pf.dumps(), end='')
#Tue Feb 25 19:13:27 EST 2020
key = value
zebra: apple
classmethod load(fp: IO) → PropertiesFile[source]

Parse the contents of the readline-supporting file-like object fp as a simple line-oriented .properties file and return a PropertiesFile instance.

fp 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.

Changed in version 0.5.0: Invalid \uXXXX escape sequences will now cause an InvalidUEscapeError to be raised

Parameters:

fp (IO) – the file from which to read the .properties document

Return type:

PropertiesFile

Raises:

InvalidUEscapeError – if an invalid \uXXXX escape sequence occurs in the input

classmethod loads(s: AnyStr) → PropertiesFile[source]

Parse the contents of the string s as a simple line-oriented .properties file and return a PropertiesFile instance.

s may be either a text string or bytes string. If it is a bytes string, its contents are decoded as Latin-1.

Changed in version 0.5.0: Invalid \uXXXX escape sequences will now cause an InvalidUEscapeError to be raised

Parameters:

s (Union[str,bytes]) – the string from which to read the .properties document

Return type:

PropertiesFile

Raises:

InvalidUEscapeError – if an invalid \uXXXX escape sequence occurs in the input

property timestamp: str | None

Added in version 0.7.0.

The value of the timestamp comment, with the comment marker, any whitespace leading up to it, and the trailing newline removed. The timestamp comment is the first comment that appears to be a valid timestamp as produced by Java 8’s Date.toString() and that does not come after any key-value pairs; if there is no such comment, the value of this property is None.

The timestamp can be changed by assigning to this property. Assigning a string s replaces the timestamp comment with the output of to_comment(s); no check is made as to whether the result is a valid timestamp comment. Assigning None or False causes the timestamp comment to be deleted (also achievable with del pf.timestamp). Assigning any other value x replaces the timestamp comment with the output of to_comment(java_timestamp(x)).

>>> pf = PropertiesFile.loads('''\
... #This is a comment.
... #Tue Feb 25 19:13:27 EST 2020
... key = value
... zebra: apple
... ''')
>>> pf.timestamp
'Tue Feb 25 19:13:27 EST 2020'
>>> pf.timestamp = 1234567890
>>> pf.timestamp
'Fri Feb 13 18:31:30 EST 2009'
>>> print(pf.dumps(), end='')
#This is a comment.
#Fri Feb 13 18:31:30 EST 2009
key = value
zebra: apple
>>> del pf.timestamp
>>> pf.timestamp is None
True
>>> print(pf.dumps(), end='')
#This is a comment.
key = value
zebra: apple

Low-Level Utilities

javaproperties.escape(field: str, ensure_ascii: bool = True) → str[source]

Escape a string so that it can be safely used as either a key or value in a .properties file. All non-ASCII characters, all nonprintable or space characters, and the characters \ # ! = : are all escaped using either the single-character escapes recognized by unescape (when they exist) or \uXXXX escapes (after converting non-BMP characters to surrogate pairs).

Changed in version 0.6.0: ensure_ascii parameter added

Parameters:

  • field (str) – the string to escape

  • ensure_ascii (bool) – if true, all non-ASCII characters will be replaced with \uXXXX escape sequences in the output; if false, non-ASCII characters will be passed through as-is

Return type:

str

javaproperties.java_timestamp(timestamp: None | bool | float | datetime = True) → str[source]

Added in version 0.2.0.

Returns a timestamp in the format produced by Java 8’s Date.toString(), e.g.:

Mon Sep 02 14:00:54 EDT 2016

If timestamp is True (the default), the current date & time is returned.

If timestamp is None or False, an empty string is returned.

If timestamp is a number, it is converted from seconds since the epoch to local time.

If timestamp is a datetime.datetime object, its value is used directly, with naïve objects assumed to be in the local timezone.

The timestamp is always constructed using the C locale.

Parameters:

timestamp (None, bool, number, or datetime.datetime) – the date & time to display

Return type:

str

javaproperties.join_key_value(key: str, value: str, separator: str = '=', ensure_ascii: bool = True) → str[source]

Join a key and value together into a single line suitable for adding to a simple line-oriented .properties file. No trailing newline is added.

>>> join_key_value('possible separators', '= : space')
'possible\\ separators=\\= \\: space'

Changed in version 0.6.0: ensure_ascii parameter added

Parameters:

  • key (str) – the key

  • value (str) – the value

  • separator (str) – the string to use for separating the key & value. Only " ", "=", and ":" (possibly with added whitespace) should ever be used as the separator.

  • ensure_ascii (bool) – if true, all non-ASCII characters will be replaced with \\uXXXX escape sequences in the output; if false, non-ASCII characters will be passed through as-is

Return type:

str

javaproperties.to_comment(comment: str, ensure_ascii: bool | None = None) → str[source]

Convert a string to a .properties file comment. Non-Latin-1 or non-ASCII characters in the string may be escaped using \uXXXX escapes (depending on the value of ensure_ascii), a # is prepended to the string, any CR LF or CR line breaks in the string are converted to LF, and a # is inserted after any line break not already followed by a # or !. No trailing newline is added.

>>> to_comment('They say foo=bar,\r\nbut does bar=foo?')
'#They say foo=bar,\n#but does bar=foo?'

Changed in version 0.6.0: ensure_ascii parameter added

Parameters:

  • comment (str) – the string to convert to a comment

  • ensure_ascii (Optional[bool]) – if true, all non-ASCII characters will be replaced with \uXXXX escape sequences in the output; if None, only non-Latin-1 characters will be escaped; if false, no characters will be escaped

Return type:

str

javaproperties.unescape(field: str) → str[source]

Decode escape sequences in a .properties key or value. The following escape sequences are recognized:

\t \n \f \r \uXXXX \\

If a backslash is followed by any other character, the backslash is dropped.

In addition, any valid UTF-16 surrogate pairs in the string after escape-decoding are further decoded into the non-BMP characters they represent. (Invalid & isolated surrogate code points are left as-is.)

Changed in version 0.5.0: Invalid \uXXXX escape sequences will now cause an InvalidUEscapeError to be raised

Parameters:

field (str) – the string to decode

Return type:

str

Raises:

InvalidUEscapeError – if an invalid \uXXXX escape sequence occurs in the input

exception javaproperties.InvalidUEscapeError(escape: str)[source]

Bases: ValueError

Added in version 0.5.0.

Raised when an invalid \uXXXX escape sequence (i.e., a \u not immediately followed by four hexadecimal digits) is encountered in a simple line-oriented .properties file

escape: str

The invalid \uXXXX escape sequence encountered

Low-Level Parsing

javaproperties.parse(src: IO | str | bytes) → Iterator[PropertiesElement][source]

Parse the given data as a simple line-oriented .properties file and return a generator of PropertiesElement objects representing the key-value pairs (as KeyValue objects), comments (as Comment objects), and blank lines (as Whitespace objects) in the input in order of occurrence.

If the same key appears multiple times in the input, a separate KeyValue object is emitted for each entry.

src may be a text string, a bytes string, or a text or binary filehandle/file-like object supporting the readline method (with or without universal newlines enabled). Bytes input is decoded as Latin-1.

Changed in version 0.5.0: Invalid \uXXXX escape sequences will now cause an InvalidUEscapeError to be raised

Changed in version 0.7.0: parse() now accepts strings as input, and it now returns a generator of custom objects instead of triples of strings

Parameters:

src (string or file-like object) – the .properties document

Return type:

Iterator[PropertiesElement]

Raises:

InvalidUEscapeError – if an invalid \uXXXX escape sequence occurs in the input

class javaproperties.PropertiesElement(source: str)[source]

Added in version 0.7.0.

Superclass of objects returned by parse()

source: str

The raw, unmodified input line (including trailing newlines)

property source_stripped: str

Like source, but with the final trailing newline and line continuation (if any) removed

class javaproperties.Comment(source: str)[source]

Added in version 0.7.0.

Subclass of PropertiesElement representing a comment

is_timestamp() → bool[source]

Returns True iff the comment’s value appears to be a valid timestamp as produced by Java 8’s Date.toString()

property source_stripped: str

Like source, but with the final trailing newline (if any) removed

property value: str

Returns the contents of the comment, with the comment marker, any whitespace leading up to it, and the trailing newline removed

class javaproperties.KeyValue(key: str, value: str, source: str)[source]

Added in version 0.7.0.

Subclass of PropertiesElement representing a key-value entry

key: str

The entry’s key, after processing escape sequences

value: str

The entry’s value, after processing escape sequences

class javaproperties.Whitespace(source: str)[source]

Added in version 0.7.0.

Subclass of PropertiesElement representing a line that is either empty or contains only whitespace (and possibly some line continuations)

Custom Encoding Error Handler

Added in version 0.6.0.

Importing javaproperties causes a custom error handler, 'javapropertiesreplace', to be automatically defined that can then be supplied as the errors argument to str.encode, open, or similar encoding operations in order to cause all unencodable characters to be replaced by \uXXXX escape sequences (with non-BMP characters converted to surrogate pairs first).

This is useful, for example, when calling javaproperties.dump(obj, fp, ensure_ascii=False) where fp has been opened using an encoding that does not contain all Unicode characters (e.g., Latin-1); in such a case, if errors='javapropertiesreplace' is supplied when opening fp, then any characters in a key or value of obj that exist outside fp’s character set will be safely encoded as .properties file format-compatible escape sequences instead of raising an error.

Note that the hexadecimal value used in a \uXXXX escape sequences is always based on the source character’s codepoint value in Unicode regardless of the target encoding:

>>> # Here we see one character encoded to the byte 0x00f0 (because that's
>>> # how the target encoding represents it) and a completely different
>>> # character encoded as the escape sequence \u00f0 (because that's its
>>> # value in Unicode):
>>> 'apple: \uF8FF; edh: \xF0'.encode('mac_roman', 'javapropertiesreplace')
b'apple: \xf0; edh: \\u00f0'
javaproperties.javapropertiesreplace_errors(e: UnicodeError) → tuple[str, int][source]

Added in version 0.6.0.

Implements the 'javapropertiesreplace' error handling (for text encodings only): unencodable characters are replaced by \uXXXX escape sequences (with non-BMP characters converted to surrogate pairs first)

Command-Line Utilities

As of version 0.4.0, the command-line programs have been split off into a separate package, javaproperties-cli, which must be installed separately in order to use them. See the package’s documentation for details.

Changelog

v0.9.0 (in development)

  • Drop support for Python 3.6 and 3.7

  • Support Python 3.11 and 3.12

  • Migrated from setuptools to hatch

v0.8.1 (2021-10-05)

  • Fix a typing issue in Python 3.9

  • Support Python 3.10

v0.8.0 (2020-11-28)

  • Drop support for Python 2.7, 3.4, and 3.5

  • Support Python 3.9

  • ensure_ascii parameter added to PropertiesFile.dump() and PropertiesFile.dumps()

  • Bugfix: When parsing XML input, empty <entry> tags now produce an empty string as a value, not None

  • Added type annotations

  • Properties and PropertiesFile no longer raise TypeError when given a non-string key or value, as type correctness is now expected to be enforced through static type checking

  • The PropertiesElement classes returned by parse() are no longer subclasses of namedtuple, but they can still be iterated over to retrieve their fields like a tuple

v0.7.0 (2020-03-09)

v0.6.0 (2020-02-28)

  • Include changelog in the Read the Docs site

  • Support Python 3.8

  • When dumping a value that begins with more than one space, only escape the first space in order to better match Java’s behavior

  • Gave dump(), dumps(), escape(), and join_key_value() an ensure_ascii parameter for optionally not escaping non-ASCII characters in output

  • Gave dump() and dumps() an ensure_ascii_comments parameter for controlling what characters in the comments parameter are escaped

  • Gave to_comment() an ensure_ascii parameter for controlling what characters are escaped

  • Added a custom encoding error handler 'javapropertiesreplace' that encodes invalid characters as \uXXXX escape sequences

v0.5.2 (2019-04-08)

  • Added an example of each format to the format descriptions in the docs

  • Fix building in non-UTF-8 environments

v0.5.1 (2018-10-25)

  • Bugfix: java_timestamp() now properly handles naïve datetime objects with fold=1

  • Include installation instructions, examples, and GitHub links in the Read the Docs site

v0.5.0 (2018-09-18)

v0.4.0 (2017-04-22)

v0.3.0 (2017-04-13)

  • Added the PropertiesFile class for preserving comments in files [#1]

  • The ordereddict package is now required under Python 2.6

v0.2.1 (2017-03-20)

  • Bugfix to javaproperties command: Don’t die horribly on missing non-ASCII keys

  • PyPy now supported

v0.2.0 (2016-11-14)

  • Added a javaproperties command for basic command-line manipulating of .properties files

  • Gave json2properties a --separator option

  • Gave json2properties and properties2json --encoding options

  • Exported the java_timestamp() function

  • to_comment() now converts CR LF and CR line endings inside comments to LF

  • Some minor documentation improvements

v0.1.0 (2016-10-02)

Initial release

javaproperties provides support for reading & writing Java .properties files (both the simple line-oriented format and XML) with a simple API based on the json module — though, for recovering Java addicts, it also includes a Properties class intended to match the behavior of Java 8’s java.util.Properties as much as is Pythonically possible.

Previous versions of javaproperties included command-line programs for basic manipulation of .properties files. As of version 0.4.0, these programs have been split off into a separate package, javaproperties-cli.

Installation

javaproperties requires Python 3.8 or higher. Just use pip for Python 3 (You have pip, right?) to install it:

python3 -m pip install javaproperties

Examples

Dump some keys & values (output order not guaranteed):

>>> properties = {"key": "value", "host:port": "127.0.0.1:80", "snowman": "☃", "goat": "🐐"}
>>> print(javaproperties.dumps(properties))
#Mon Sep 26 14:57:44 EDT 2016
key=value
goat=\ud83d\udc10
host\:port=127.0.0.1\:80
snowman=\u2603

Load some keys & values:

>>> javaproperties.loads('''
... #Mon Sep 26 14:57:44 EDT 2016
... key = value
... goat: \\ud83d\\udc10
... host\\:port=127.0.0.1:80
... #foo = bar
... snowman   ☃
... ''')
{'goat': '🐐', 'host:port': '127.0.0.1:80', 'key': 'value', 'snowman': '☃'}

Dump some properties to a file and read them back in again:

>>> with open('example.properties', 'w', encoding='latin-1') as fp:
...     javaproperties.dump(properties, fp)
...
>>> with open('example.properties', 'r', encoding='latin-1') as fp:
...     javaproperties.load(fp)
...
{'goat': '🐐', 'host:port': '127.0.0.1:80', 'key': 'value', 'snowman': '☃'}

Sort the properties you’re dumping:

>>> print(javaproperties.dumps(properties, sort_keys=True))
#Mon Sep 26 14:57:44 EDT 2016
goat=\ud83d\udc10
host\:port=127.0.0.1\:80
key=value
snowman=\u2603

Turn off the timestamp:

>>> print(javaproperties.dumps(properties, timestamp=None))
key=value
goat=\ud83d\udc10
host\:port=127.0.0.1\:80
snowman=\u2603

Use your own timestamp (automatically converted to local time):

>>> print(javaproperties.dumps(properties, timestamp=1234567890))
#Fri Feb 13 18:31:30 EST 2009
key=value
goat=\ud83d\udc10
host\:port=127.0.0.1\:80
snowman=\u2603

Dump as XML:

>>> print(javaproperties.dumps_xml(properties))
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
<entry key="key">value</entry>
<entry key="goat">🐐</entry>
<entry key="host:port">127.0.0.1:80</entry>
<entry key="snowman">☃</entry>
</properties>

New in v0.6.0: Dump Unicode characters as-is instead of escaping them:

>>> print(javaproperties.dumps(properties, ensure_ascii=False))
#Tue Feb 25 19:13:27 EST 2020
key=value
goat=🐐
host\:port=127.0.0.1\:80
snowman=☃

Indices and tables