parsing .properties file in Python
PythonKey ValueIniPython Problem Overview
The ConfigParser module raises an exception if one parses a simple Java-style .properties file, whose content is key-value pairs (i..e without INI-style section headers). Is there some workaround?
Python Solutions
Solution 1 - Python
Say you have, e.g.:
$ cat my.props
first: primo
second: secondo
third: terzo
i.e. would be a .config format except that it's missing a leading section name. Then, it easy to fake the section header:
import ConfigParser
class FakeSecHead(object):
def __init__(self, fp):
self.fp = fp
self.sechead = '[asection]\n'
def readline(self):
if self.sechead:
try:
return self.sechead
finally:
self.sechead = None
else:
return self.fp.readline()
usage:
cp = ConfigParser.SafeConfigParser()
cp.readfp(FakeSecHead(open('my.props')))
print cp.items('asection')
output:
[('second', 'secondo'), ('third', 'terzo'), ('first', 'primo')]
Solution 2 - Python
I thought MestreLion's "read_string" comment was nice and simple and deserved an example.
For Python 3.2+, you can implement the "dummy section" idea like this:
with open(CONFIG_PATH, 'r') as f:
config_string = '[dummy_section]\n' + f.read()
config = configparser.ConfigParser()
config.read_string(config_string)
Solution 3 - Python
My solution is to use StringIO and prepend a simple dummy header:
import StringIO
import os
config = StringIO.StringIO()
config.write('[dummysection]\n')
config.write(open('myrealconfig.ini').read())
config.seek(0, os.SEEK_SET)
import ConfigParser
cp = ConfigParser.ConfigParser()
cp.readfp(config)
somevalue = cp.getint('dummysection', 'somevalue')
Solution 4 - Python
Alex Martelli's answer above does not work for Python 3.2+: readfp() has been replaced by read_file(), and it now takes an iterator instead of using the readline() method.
Here's a snippet that uses the same approach, but works in Python 3.2+.
>>> import configparser
>>> def add_section_header(properties_file, header_name):
... # configparser.ConfigParser requires at least one section header in a properties file.
... # Our properties file doesn't have one, so add a header to it on the fly.
... yield '[{}]\n'.format(header_name)
... for line in properties_file:
... yield line
...
>>> file = open('my.props', encoding="utf_8")
>>> config = configparser.ConfigParser()
>>> config.read_file(add_section_header(file, 'asection'), source='my.props')
>>> config['asection']['first']
'primo'
>>> dict(config['asection'])
{'second': 'secondo', 'third': 'terzo', 'first': 'primo'}
>>>
Solution 5 - Python
with open('some.properties') as file:
props = dict(line.strip().split('=', 1) for line in file)
maxsplit=1 is important if there are equal signs in the value (e.g. someUrl=https://some.site.com/endpoint?id=some-value&someotherkey=value)
Solution 6 - Python
YAY! another version
Based on this answer (the addition is using a dict, with statement, and supporting the % character)
import ConfigParser
import StringIO
import os
def read_properties_file(file_path):
with open(file_path) as f:
config = StringIO.StringIO()
config.write('[dummy_section]\n')
config.write(f.read().replace('%', '%%'))
config.seek(0, os.SEEK_SET)
cp = ConfigParser.SafeConfigParser()
cp.readfp(config)
return dict(cp.items('dummy_section'))
Usage
props = read_properties_file('/tmp/database.properties')
# It will raise if `name` is not in the properties file
name = props['name']
# And if you deal with optional settings, use:
connection_string = props.get('connection-string')
password = props.get('password')
print name, connection_string, password
the .properties file used in my example
name=mongo
connection-string=mongodb://...
password=my-password%1234
Edit 2015-11-06
Thanks to Neill Lima mentioning there was an issue with the % character.
The reason for that is ConfigParser designed to parse .ini files. The % character is a special syntax. in order to use the % character simply added a a replace for % with %% according to .ini syntax.
Solution 7 - Python
from pyjavaproperties import Properties
p = Properties()
p.load(open('test.properties'))
p.list()
print p
print p.items()
print p['name3']
p['name3'] = 'changed = value'
print p['name3']
p['new key'] = 'new value'
p.store(open('test2.properties','w'))
Solution 8 - Python
This answer suggests using itertools.chain in Python 3.
from configparser import ConfigParser
from itertools import chain
parser = ConfigParser()
with open("foo.conf") as lines:
lines = chain(("[dummysection]",), lines) # This line does the trick.
parser.read_file(lines)
Solution 9 - Python
with open('mykeyvaluepairs.properties') as f:
defaults = dict([line.split() for line in f])
config = configparser.ConfigParser(defaults)
config.add_section('dummy_section')
Now config.get('dummy_section', option) will return 'option' from the DEFAULT section.
or:
with open('mykeyvaluepairs.properties') as f:
properties = dict([line.split() for line in f])
config = configparser.ConfigParser()
config.add_section('properties')
for prop, val in properties.items():
config.set('properties', prop, val)
In which case config.get('properties', option) doesn't resort to the default section.
Solution 10 - Python
Yet another answer for python2.7 based on Alex Martelli's answer
import ConfigParser
class PropertiesParser(object):
"""Parse a java like properties file
Parser wrapping around ConfigParser allowing reading of java like
properties file. Based on stackoverflow example:
https://stackoverflow.com/questions/2819696/parsing-properties-file-in-python/2819788#2819788
Example usage
-------------
>>> pp = PropertiesParser()
>>> props = pp.parse('/home/kola/configfiles/dev/application.properties')
>>> print props
"""
def __init__(self):
self.secheadname = 'fakeSectionHead'
self.sechead = '[' + self.secheadname + ']\n'
def readline(self):
if self.sechead:
try:
return self.sechead
finally:
self.sechead = None
else:
return self.fp.readline()
def parse(self, filepath):
self.fp = open(filepath)
cp = ConfigParser.SafeConfigParser()
cp.readfp(self)
self.fp.close()
return cp.items(self.secheadname)