Related
I want to dump a python object into a YAML string that only contains a single line. However, ruamel.yaml.safe_dump appends newline characters as well as (sometimes) '...'
Dumping for example list or dict objects appends a single newline character:
import ruamel.yaml as yaml
yaml.safe_dump([1, None], default_flow_style=None)
Outputs: '[1, null]\n'
The output I need is: '[1, null]'
When dumping "scalar" objects, even more is appended:
import ruamel.yaml as yaml
yaml.safe_dump(None, default_flow_style=None)
Outputs: 'null\n...\n'
The output I need is: 'null'
Both expected outputs are valid YAML syntax I think, i.e.
yaml.safe_load('null')
correctly returns None.
Is there any way (besides manually removing the trailing line breaks and '...', which is very hacky) to achieve what I want?
You should not be using the old API in ruamel.yaml , it's deprecated and about to be removed.
If you want everything on one line, you should probably use .default_flow_style = True
depending on how complex your data-structure can become, and widen the output so you
don't get linewraps.
Contrary to JSON, YAML normally appends a newline, so it is best to just transform the output
to hack anything of after the first one.
import sys
import ruamel.yaml
class DSL:
def __init__(self):
pass
#property
def yaml(self):
try:
return self._yaml
except AttributeError:
pass
yaml = ruamel.yaml.YAML(typ='safe')
yaml.default_flow_style = True
yaml.width = 2048
self._yaml = yaml
return yaml
def __call__(self, data, stream=sys.stdout):
def strip_nl(s):
result, rest = s.split('\n', 1)
if rest not in ['', '...\n']:
print('multi-line YAML output', repr(rest))
sys.exit(1)
return result
self.yaml.dump(data, stream, transform=strip_nl)
dsl = DSL()
sys.stdout.write('|')
dsl([1, None])
sys.stdout.write('|\n')
sys.stdout.write('|')
dsl(None)
sys.stdout.write('|\n')
sys.stdout.write('|')
dsl(dict(a=[1, None], b=42))
sys.stdout.write('|\n')
which gives:
|[1, null]|
|null|
|{a: [1, null], b: 42}|
The typical ConfigParser generated file looks like:
[Section]
bar=foo
[Section 2]
bar2= baz
Now, is there a way to index lists like, for instance:
[Section 3]
barList={
item1,
item2
}
Related question: Python’s ConfigParser unique keys per section
I am using a combination of ConfigParser and JSON:
[Foo]
fibs: [1,1,2,3,5,8,13]
just read it with:
>>> json.loads(config.get("Foo","fibs"))
[1, 1, 2, 3, 5, 8, 13]
You can even break lines if your list is long (thanks #peter-smit):
[Bar]
files_to_check = [
"/path/to/file1",
"/path/to/file2",
"/path/to/another file with space in the name"
]
Of course i could just use JSON, but i find config files much more readable, and the [DEFAULT] Section very handy.
There is nothing stopping you from packing the list into a delimited string and then unpacking it once you get the string from the config. If you did it this way your config section would look like:
[Section 3]
barList=item1,item2
It's not pretty but it's functional for most simple lists.
I recently implemented this with a dedicated section in a config file for a list:
[paths]
path1 = /some/path/
path2 = /another/path/
...
and using config.items( "paths" ) to get an iterable list of path items, like so:
path_items = config.items( "paths" )
for key, path in path_items:
#do something with path
One thing a lot of people don't know is that multi-line configuration-values are allowed. For example:
;test.ini
[hello]
barlist =
item1
item2
The value of config.get('hello','barlist') will now be:
"\nitem1\nitem2"
Which you easily can split with the splitlines method (don't forget to filter empty items).
If we look to a big framework like Pyramid they are using this technique:
def aslist_cronly(value):
if isinstance(value, string_types):
value = filter(None, [x.strip() for x in value.splitlines()])
return list(value)
def aslist(value, flatten=True):
""" Return a list of strings, separating the input based on newlines
and, if flatten=True (the default), also split on spaces within
each line."""
values = aslist_cronly(value)
if not flatten:
return values
result = []
for value in values:
subvalues = value.split()
result.extend(subvalues)
return result
Source
Myself, I would maybe extend the ConfigParser if this is a common thing for you:
class MyConfigParser(ConfigParser):
def getlist(self,section,option):
value = self.get(section,option)
return list(filter(None, (x.strip() for x in value.splitlines())))
def getlistint(self,section,option):
return [int(x) for x in self.getlist(section,option)]
Note that there are a few things to look out for when using this technique
New lines that are items should start with whitespace (e.g. a space or a tab)
All following lines that start with whitespace are considered to be part of the previous item. Also if it has an = sign or if it starts with a ; following the whitespace.
No mention of the converters kwarg for ConfigParser() in any of these answers was rather disappointing.
According to the documentation you can pass a dictionary to ConfigParser that will add a get method for both the parser and section proxies. So for a list:
example.ini
[Germ]
germs: a,list,of,names, and,1,2, 3,numbers
Parser example:
cp = ConfigParser(converters={'list': lambda x: [i.strip() for i in x.split(',')]})
cp.read('example.ini')
cp.getlist('Germ', 'germs')
['a', 'list', 'of', 'names', 'and', '1', '2', '3', 'numbers']
cp['Germ'].getlist('germs')
['a', 'list', 'of', 'names', 'and', '1', '2', '3', 'numbers']
This is my personal favorite as no subclassing is necessary and I don't have to rely on an end user to perfectly write JSON or a list that can be interpreted by ast.literal_eval.
If you want to literally pass in a list then you can use:
ast.literal_eval()
For example configuration:
[section]
option=["item1","item2","item3"]
The code is:
import ConfigParser
import ast
my_list = ast.literal_eval(config.get("section", "option"))
print(type(my_list))
print(my_list)
output:
<type'list'>
["item1","item2","item3"]
I landed here seeking to consume this...
[global]
spys = richard.sorge#cccp.gov, mata.hari#deutschland.gov
The answer is to split it on the comma and strip the spaces:
SPYS = [e.strip() for e in parser.get('global', 'spys').split(',')]
To get a list result:
['richard.sorge#cccp.gov', 'mata.hari#deutschland.gov']
It may not answer the OP's question exactly but might be the simple answer some people are looking for.
This is what I use for lists:
config file content:
[sect]
alist = a
b
c
code :
l = config.get('sect', 'alist').split('\n')
it work for strings
in case of numbers
config content:
nlist = 1
2
3
code:
nl = config.get('sect', 'alist').split('\n')
l = [int(nl) for x in nl]
thanks.
So another way, which I prefer, is to just split the values, for example:
#/path/to/config.cfg
[Numbers]
first_row = 1,2,4,8,12,24,36,48
Could be loaded like this into a list of strings or integers, as follows:
import configparser
config = configparser.ConfigParser()
config.read('/path/to/config.cfg')
# Load into a list of strings
first_row_strings = config.get('Numbers', 'first_row').split(',')
# Load into a list of integers
first_row_integers = [int(x) for x in config.get('Numbers', 'first_row').split(',')]
This method prevents you from needing to wrap your values in brackets to load as JSON.
I completed similar task in my project with section with keys without values:
import configparser
# allow_no_value param says that no value keys are ok
config = configparser.ConfigParser(allow_no_value=True)
# overwrite optionxform method for overriding default behaviour (I didn't want lowercased keys)
config.optionxform = lambda optionstr: optionstr
config.read('./app.config')
features = list(config['FEATURES'].keys())
print(features)
Output:
['BIOtag', 'TextPosition', 'IsNoun', 'IsNomn']
app.config:
[FEATURES]
BIOtag
TextPosition
IsNoun
IsNomn
Only primitive types are supported for serialization by config parser. I would use JSON or YAML for that kind of requirement.
To take Grr's answer (my favorite) a step further, instead of enclosing list items in quotes in the .ini file, you can use the map function. This allows you to pythonically specify list item datatypes.
Config file:
[section]
listKey1: 1001, 1002, 1003
listKey2: AAAA, BBBB, CCCC
Code:
cfgFile = 'config.ini'
parser = ConfigParser(converters={'list': lambda x: [i.strip() for i in x.split(',')]})
parser.read(cfgFile)
list1 = list(map(int, parser.getlist('section', 'listKey1')))
list2 = list(map(str, parser.getlist('section', 'listKey2')))
print(list1)
print(list2)
Output:
[1001, 1002, 1003]
['AAAA', 'BBBB', 'CCCC']
If this is your config.ini:
[Section 3]
barList=item1,item2
Then with configparser you could do this:
from configparser import ConfigParser
config = ConfigParser()
config.read('config.ini')
my_list = config['Section 3']['barList'].split(',')
You will get:
my_list = ['item1', 'item2']
The split()-method will return a list, see Python string docs.
If you have white spaces in your config.ini like this:
[Section 3]
barList= item1, item2
Then you'd better do this:
my_list = [x.strip() for x in config['Section 3']['barList'].split(',')]
If your items are numbers (integers for instance), just apply:
my_list_of_ints = list(map(int, my_list))
You will get:
my_list_of_ints = [item1, item2]
I faced the same problem in the past. If you need more complex lists, consider creating your own parser by inheriting from ConfigParser. Then you would overwrite the get method with that:
def get(self, section, option):
""" Get a parameter
if the returning value is a list, convert string value to a python list"""
value = SafeConfigParser.get(self, section, option)
if (value[0] == "[") and (value[-1] == "]"):
return eval(value)
else:
return value
With this solution you will also be able to define dictionaries in your config file.
But be careful! This is not as safe: this means anyone could run code through your config file. If security is not an issue in your project, I would consider using directly python classes as config files. The following is much more powerful and expendable than a ConfigParser file:
class Section
bar = foo
class Section2
bar2 = baz
class Section3
barList=[ item1, item2 ]
import ConfigParser
import os
class Parser(object):
"""attributes may need additional manipulation"""
def __init__(self, section):
"""section to retun all options on, formatted as an object
transforms all comma-delimited options to lists
comma-delimited lists with colons are transformed to dicts
dicts will have values expressed as lists, no matter the length
"""
c = ConfigParser.RawConfigParser()
c.read(os.path.join(os.path.dirname(__file__), 'config.cfg'))
self.section_name = section
self.__dict__.update({k:v for k, v in c.items(section)})
#transform all ',' into lists, all ':' into dicts
for key, value in self.__dict__.items():
if value.find(':') > 0:
#dict
vals = value.split(',')
dicts = [{k:v} for k, v in [d.split(':') for d in vals]]
merged = {}
for d in dicts:
for k, v in d.items():
merged.setdefault(k, []).append(v)
self.__dict__[key] = merged
elif value.find(',') > 0:
#list
self.__dict__[key] = value.split(',')
So now my config.cfg file, which could look like this:
[server]
credentials=username:admin,password:$3<r3t
loggingdirs=/tmp/logs,~/logs,/var/lib/www/logs
timeoutwait=15
Can be parsed into fine-grained-enough objects for my small project.
>>> import config
>>> my_server = config.Parser('server')
>>> my_server.credentials
{'username': ['admin'], 'password', ['$3<r3t']}
>>> my_server.loggingdirs:
['/tmp/logs', '~/logs', '/var/lib/www/logs']
>>> my_server.timeoutwait
'15'
This is for very quick parsing of simple configs, you lose all ability to fetch ints, bools, and other types of output without either transforming the object returned from Parser, or re-doing the parsing job accomplished by the Parser class elsewhere.
json.loads & ast.literal_eval seems to be working but simple list within config is treating each character as byte so returning even square bracket....
meaning if config has fieldvalue = [1,2,3,4,5]
then config.read(*.cfg)
config['fieldValue'][0] returning [ in place of 1
As mentioned by Peter Smit (https://stackoverflow.com/a/11866695/7424596)
You might want to extend ConfigParser, in addition, an Interpolator can be used to automatically convert into and from the list.
For reference at the bottom you can find code which automatically converts config like:
[DEFAULT]
keys = [
Overall cost structure, Capacity, RAW MATERIALS,
BY-PRODUCT CREDITS, UTILITIES, PLANT GATE COST,
PROCESS DESCRIPTION, AT 50% CAPACITY, PRODUCTION COSTS,
INVESTMENT, US$ MILLION, PRODUCTION COSTS, US ¢/LB,
VARIABLE COSTS, PRODUCTION COSTS, MAINTENANCE MATERIALS
]
So if you request keys you will get:
<class 'list'>: ['Overall cost structure', 'Capacity', 'RAW MATERIALS', 'BY-PRODUCT CREDITS', 'UTILITIES', 'PLANT GATE COST', 'PROCESS DESCRIPTION', 'AT 50% CAPACITY', 'PRODUCTION COSTS', 'INVESTMENT', 'US$ MILLION', 'PRODUCTION COSTS', 'US ¢/LB', 'VARIABLE COSTS', 'PRODUCTION COSTS', 'MAINTENANCE MATERIALS']
Code:
class AdvancedInterpolator(Interpolation):
def before_get(self, parser, section, option, value, defaults):
is_list = re.search(parser.LIST_MATCHER, value)
if is_list:
return parser.getlist(section, option, raw=True)
return value
class AdvancedConfigParser(ConfigParser):
_DEFAULT_INTERPOLATION = AdvancedInterpolator()
LIST_SPLITTER = '\s*,\s*'
LIST_MATCHER = '^\[([\s\S]*)\]$'
def _to_list(self, str):
is_list = re.search(self.LIST_MATCHER, str)
if is_list:
return re.split(self.LIST_SPLITTER, is_list.group(1))
else:
return re.split(self.LIST_SPLITTER, str)
def getlist(self, section, option, conv=lambda x:x.strip(), *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self._get_conv(
section, option,
lambda value: [conv(x) for x in self._to_list(value)],
raw=raw,
vars=vars,
fallback=fallback,
**kwargs
)
def getlistint(self, section, option, *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self.getlist(section, option, int, raw=raw, vars=vars,
fallback=fallback, **kwargs)
def getlistfloat(self, section, option, *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self.getlist(section, option, float, raw=raw, vars=vars,
fallback=fallback, **kwargs)
def getlistboolean(self, section, option, *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self.getlist(section, option, self._convert_to_boolean,
raw=raw, vars=vars, fallback=fallback, **kwargs)
Ps keep in mind importance of indentdation. As reads in ConfigParser doc string:
Values can span multiple lines, as long as they are indented deeper
than the first line of the value. Depending on the parser's mode, blank
lines may be treated as parts of multiline values or ignored.
you can use list in config file then parse it in python
from ast import literal_eval
literal_eval("[1,2,3,4]")
import json
json.loads("[1,2,3,4]")
and also you can use json file behind your config file like this:
your config file :
[A]
json_dis = .example.jason
--------------------
your code :
import configparser
config = configparser.ConfigParser()
config.read('config.ini')
# getting items of section A
config.items('A')
# result is a list of key-values
An improvement on split(',') might be to treat the comma separated values as a record in a CSV file
import csv
my_list = list(csv.reader([config['Section 3']['barList']], dialect=csv.excel))[0]
You can configure a dialect to parse whatever style of CSV you like.
I need to break down .yml files into 3 parts: Header, Working (the part I need to edit), and footer. The header is everything that comes before the 'Resource: ' block, and the footer is everything after the resource block. I essentially need to create code that creates 3 lists, dictionaries, strings, whatever works, that holds these three sections of the YAML file, then allows me to run more code against the working piece, then concatenate all of them together at the end and produce the new document with the same indentations. No changes should be made to the header or the tail.
Note: I've looked up everything about yaml parsing and whatnot, but cannot seem to implement the advice I've found effectively. A solution that does not involve importing yaml would be preferred, but if you must, please explain what is really going on with the import yaml code so I can understand what I'm messing up.
Files that contain one or more YAML documents (in short: a YAML file, which, since
Sept. 2006, has been recommended to have the extension .yaml), are
text files and can be concatenated from parts as such. The only requirement being
that in the end you have a text file that is a valid YAML file.
The easiest is of course to have the Header and footer in separate
files for that, but as you are talking about multiple YAML files this
soon becomes unwieldy. It is however always possible to do some basic
parsing of the file contents.
Since your Working part starts with Resource:, and you indicate 3
lists or dictionaries (you cannot have three strings at the root of a
YAML document). The root level data structure of your YAML document
needs to be a either a mapping, and everything else, except for the
keys to that mapping need to be indented (in theory it only needs to
be indented more, but in practise this almost always means that the
keys are not indented), Like (m.yaml):
# header
a: 1
b:
- 2
- c: 3 # end of header
Resource:
# footer
c:
d: "the end" # really
or the root level needs to be a sequence (s.yaml):
# header
- a: 1
b:
- 2
- c: 3
- 42 # end of header
- Resource:
# footer
- c:
d: "the end" # really
both can easily be split without loading the YAML, here is the example code for doing so for
the file with the root level mapping:
from pathlib import Path
from ruamel.yaml import YAML
inf = Path('m.yaml')
header = [] # list of lines
resource = []
footer = []
for line in inf.open():
if not resource:
if line.startswith('Resource:'): # check if we are at end of the header
resource.append(line)
continue
header.append(line)
continue
elif not footer:
if not line or line[0] == ' ': # still in the resource part
resource.append(line)
continue
footer.append(line)
# you now have lists of lines for the header and the footer
# define the new data structure for the resource this is going to be a single key/value dict
upd_resource = dict(Resource=['some text', 'for the resource spec', {'a': 1, 'b': 2}])
# write the header lines, dump the resource lines, write the footer lines
outf = Path('out.yaml')
with outf.open('w') as out:
out.write(''.join(header))
yaml = YAML()
yaml.indent(mapping=2, sequence=2, offset=0) # the default values
yaml.dump(upd_resource, out)
out.write(''.join(footer))
print(outf.read_text())
this gives:
# header
a: 1
b:
- 2
- c: 3 # end of header
Resource:
- some text
- for the resource spec
- a: 1
b: 2
# footer
c:
d: "the end" # really
Doing the same while parsing the YAML file is not more difficult. The following automitcally handles
both cases (whether the root level is a mapping or a sequence):
from pathlib import Path
from ruamel.yaml import YAML
inf = Path('s.yaml')
upd_resource_val = ['some text', 'for the resource spec', {'a': 1, 'b': 2}]
outf = Path('out.yaml')
yaml = ruamel.yaml.YAML()
yaml.indent(mapping=2, sequence=2, offset=0)
yaml.preserve_quotes = True
data = yaml.load(inf)
if isinstance(data, dict):
data['Resource'] = upd_resource_val
else: # assume a list,
for item in data: # search for the item which has as value a dict with key Resource
try:
if 'Resource' in item:
item['Resource'] = upd_resource_val
break
except TypeError:
pass
yaml.dump(data, outf)
This creates the following out.yaml:
# header
- a: 1
b:
- 2
- c: 3
- 42 # end of header
- Resource:
- some text
- for the resource spec
- a: 1
b: 2
# footer
- c:
d: "the end" # really
If the m.yaml file had been the input, the output would have
been exactly the same as with the text based "concatenation" example code.
When using ConfigParser module I would like to use values containing of multiple words set in cfg file. In this case seems trivial for me to surround the string with quotes like (example.cfg):
[GENERAL]
onekey = "value in some words"
My problem is that in this case python appends the quotes to the string as well when using the value like this:
config = ConfigParser()
config.read(["example.cfg"])
print config.get('GENERAL', 'onekey')
I am sure there is an in-built feature to manage to print only 'value in some words' instead of '"value in some words"'. How is it possible? Thanks.
I didn't see anything in the configparser manual, but you could just use the .strip method of strings to get rid of the leading and trailing double quotes.
>>> s = '"hello world"'
>>> s
'"hello world"'
>>> s.strip('"')
'hello world'
>>> s2 = "foo"
>>> s2.strip('"')
'foo'
As you can see, .strip does not modify the string if it does not start and end with the specified string.
import ConfigParser
class MyConfigParser(ConfigParser.RawConfigParser):
def get(self, section, option):
val = ConfigParser.RawConfigParser.get(self, section, option)
return val.strip('"')
if __name__ == "__main__":
#config = ConfigParser.RawConfigParser()
config = MyConfigParser()
config.read(["example.cfg"])
print config.get('GENERAL', 'onekey')
Sorry, the solution was trivial as well - I can simply leave the quotes, it looks python simply takes the right side of equal sign.
The question is quite old already, but in 2.6 at least you don't need to use quotes as spaces are retained.
from ConfigParser import RawConfigParser
from StringIO import StringIO
s = RawConfigParser()
s.readfp(StringIO('[t]\na= 1 2 3'))
s.get('t','a')
> '1 2 3'
That doesn't apply though either to leading or trailing spaces! If you want to retain those, you will need to enclose them in quotes an proceed as suggested. Refrain from using the eval keyword as you'll have a huge security hole.
can write configuration reading function as follows, which returns configuration in dictionary form.
def config_reader():
"""
Reads configuration from configuration file.
"""
configuration = ConfigParser.ConfigParser()
configuration.read(__file__.split('.')[0] + '.cfg')
config = {}
for section in configuration.sections():
config[section] = {}
for option in configuration.options(section):
config[section][option] = (configuration.get(section, option)).strip('"').strip("'")
return config
Davey,
As you say you can just leave the quotes off your string.
For a project I'm working on I wanted to be able to represent almost any Python string literal as a value for some of my config options and more to the point I wanted to be able to handle some of them as raw string literals. (I want that config to be able to handle things like \n, \x1b, and so on).
In that case I used something like:
def EvalStr(s, raw=False):
r'''Attempt to evaluate a value as a Python string literal or
return s unchanged.
Attempts are made to wrap the value in one, then the
form of triple quote. If the target contains both forms
of triple quote, we'll just punt and return the original
argument unmodified.
Examples: (But note that this docstring is raw!)
>>> EvalStr(r'this\t is a test\n and only a \x5c test')
'this\t is a test\n and only a \\ test'
>>> EvalStr(r'this\t is a test\n and only a \x5c test', 'raw')
'this\\t is a test\\n and only a \\x5c test'
'''
results = s ## Default returns s unchanged
if raw:
tmplate1 = 'r"""%s"""'
tmplate2 = "r'''%s'''"
else:
tmplate1 = '"""%s"""'
tmplate2 = "'''%s'''"
try:
results = eval(tmplate1 % s)
except SyntaxError:
try:
results = eval(tmplate2 %s)
except SyntaxError:
pass
return results
... which I think will handle anything that doesn't contain both triple-single and triple-double quoted strings.
(That one corner case is way beyond my requirements).
There is an oddity of this code here on SO; the Syntax highlighter seems to be confused by
the fact that my docstring is a raw string. That was necessary to make doctest happy for this particular function).
I had to face the same problem. Instead of a configparser object, I prefer to work with normal dictionaries. So first I read the .ini file, then convert the configparser object to dict, and finally I remove quotes (or apostrophes) from string values. Here is my solution:
preferences.ini
[GENERAL]
onekey = "value in some words"
[SETTINGS]
resolution = '1024 x 768'
example.py
#!/usr/bin/env python3
from pprint import pprint
import preferences
prefs = preferences.Preferences("preferences.ini")
d = prefs.as_dict()
pprint(d)
preferences.py
import sys
import configparser
import json
from pprint import pprint
def remove_quotes(original):
d = original.copy()
for key, value in d.items():
if isinstance(value, str):
s = d[key]
if s.startswith(('"', "'")):
s = s[1:]
if s.endswith(('"', "'")):
s = s[:-1]
d[key] = s
# print(f"string found: {s}")
if isinstance(value, dict):
d[key] = remove_quotes(value)
#
return d
class Preferences:
def __init__(self, preferences_ini):
self.preferences_ini = preferences_ini
self.config = configparser.ConfigParser()
self.config.read(preferences_ini)
self.d = self.to_dict(self.config._sections)
def as_dict(self):
return self.d
def to_dict(self, config):
"""
Nested OrderedDict to normal dict.
Also, remove the annoying quotes (apostrophes) from around string values.
"""
d = json.loads(json.dumps(config))
d = remove_quotes(d)
return d
The line d = remove_quotes(d) is responsible for removing the quotes. Comment / uncomment this line to see the difference.
Output:
$ ./example.py
{'GENERAL': {'onekey': 'value in some words'},
'SETTINGS': {'resolution': '1024 x 768'}}
At this situation, the most simple solution is "eval()".
However, you may worry about the security stuff.But you could still do this by:
def literal_eval(node_or_string):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts,booleans,
and None.
"""
as a sample:
import ast
config = ConfigParser()
config.read(["example.cfg"])
print ast.literal_eval(config.get('GENERAL', 'onekey'))
# value in some words
The typical ConfigParser generated file looks like:
[Section]
bar=foo
[Section 2]
bar2= baz
Now, is there a way to index lists like, for instance:
[Section 3]
barList={
item1,
item2
}
Related question: Python’s ConfigParser unique keys per section
I am using a combination of ConfigParser and JSON:
[Foo]
fibs: [1,1,2,3,5,8,13]
just read it with:
>>> json.loads(config.get("Foo","fibs"))
[1, 1, 2, 3, 5, 8, 13]
You can even break lines if your list is long (thanks #peter-smit):
[Bar]
files_to_check = [
"/path/to/file1",
"/path/to/file2",
"/path/to/another file with space in the name"
]
Of course i could just use JSON, but i find config files much more readable, and the [DEFAULT] Section very handy.
There is nothing stopping you from packing the list into a delimited string and then unpacking it once you get the string from the config. If you did it this way your config section would look like:
[Section 3]
barList=item1,item2
It's not pretty but it's functional for most simple lists.
I recently implemented this with a dedicated section in a config file for a list:
[paths]
path1 = /some/path/
path2 = /another/path/
...
and using config.items( "paths" ) to get an iterable list of path items, like so:
path_items = config.items( "paths" )
for key, path in path_items:
#do something with path
One thing a lot of people don't know is that multi-line configuration-values are allowed. For example:
;test.ini
[hello]
barlist =
item1
item2
The value of config.get('hello','barlist') will now be:
"\nitem1\nitem2"
Which you easily can split with the splitlines method (don't forget to filter empty items).
If we look to a big framework like Pyramid they are using this technique:
def aslist_cronly(value):
if isinstance(value, string_types):
value = filter(None, [x.strip() for x in value.splitlines()])
return list(value)
def aslist(value, flatten=True):
""" Return a list of strings, separating the input based on newlines
and, if flatten=True (the default), also split on spaces within
each line."""
values = aslist_cronly(value)
if not flatten:
return values
result = []
for value in values:
subvalues = value.split()
result.extend(subvalues)
return result
Source
Myself, I would maybe extend the ConfigParser if this is a common thing for you:
class MyConfigParser(ConfigParser):
def getlist(self,section,option):
value = self.get(section,option)
return list(filter(None, (x.strip() for x in value.splitlines())))
def getlistint(self,section,option):
return [int(x) for x in self.getlist(section,option)]
Note that there are a few things to look out for when using this technique
New lines that are items should start with whitespace (e.g. a space or a tab)
All following lines that start with whitespace are considered to be part of the previous item. Also if it has an = sign or if it starts with a ; following the whitespace.
No mention of the converters kwarg for ConfigParser() in any of these answers was rather disappointing.
According to the documentation you can pass a dictionary to ConfigParser that will add a get method for both the parser and section proxies. So for a list:
example.ini
[Germ]
germs: a,list,of,names, and,1,2, 3,numbers
Parser example:
cp = ConfigParser(converters={'list': lambda x: [i.strip() for i in x.split(',')]})
cp.read('example.ini')
cp.getlist('Germ', 'germs')
['a', 'list', 'of', 'names', 'and', '1', '2', '3', 'numbers']
cp['Germ'].getlist('germs')
['a', 'list', 'of', 'names', 'and', '1', '2', '3', 'numbers']
This is my personal favorite as no subclassing is necessary and I don't have to rely on an end user to perfectly write JSON or a list that can be interpreted by ast.literal_eval.
If you want to literally pass in a list then you can use:
ast.literal_eval()
For example configuration:
[section]
option=["item1","item2","item3"]
The code is:
import ConfigParser
import ast
my_list = ast.literal_eval(config.get("section", "option"))
print(type(my_list))
print(my_list)
output:
<type'list'>
["item1","item2","item3"]
I landed here seeking to consume this...
[global]
spys = richard.sorge#cccp.gov, mata.hari#deutschland.gov
The answer is to split it on the comma and strip the spaces:
SPYS = [e.strip() for e in parser.get('global', 'spys').split(',')]
To get a list result:
['richard.sorge#cccp.gov', 'mata.hari#deutschland.gov']
It may not answer the OP's question exactly but might be the simple answer some people are looking for.
This is what I use for lists:
config file content:
[sect]
alist = a
b
c
code :
l = config.get('sect', 'alist').split('\n')
it work for strings
in case of numbers
config content:
nlist = 1
2
3
code:
nl = config.get('sect', 'alist').split('\n')
l = [int(nl) for x in nl]
thanks.
So another way, which I prefer, is to just split the values, for example:
#/path/to/config.cfg
[Numbers]
first_row = 1,2,4,8,12,24,36,48
Could be loaded like this into a list of strings or integers, as follows:
import configparser
config = configparser.ConfigParser()
config.read('/path/to/config.cfg')
# Load into a list of strings
first_row_strings = config.get('Numbers', 'first_row').split(',')
# Load into a list of integers
first_row_integers = [int(x) for x in config.get('Numbers', 'first_row').split(',')]
This method prevents you from needing to wrap your values in brackets to load as JSON.
I completed similar task in my project with section with keys without values:
import configparser
# allow_no_value param says that no value keys are ok
config = configparser.ConfigParser(allow_no_value=True)
# overwrite optionxform method for overriding default behaviour (I didn't want lowercased keys)
config.optionxform = lambda optionstr: optionstr
config.read('./app.config')
features = list(config['FEATURES'].keys())
print(features)
Output:
['BIOtag', 'TextPosition', 'IsNoun', 'IsNomn']
app.config:
[FEATURES]
BIOtag
TextPosition
IsNoun
IsNomn
Only primitive types are supported for serialization by config parser. I would use JSON or YAML for that kind of requirement.
To take Grr's answer (my favorite) a step further, instead of enclosing list items in quotes in the .ini file, you can use the map function. This allows you to pythonically specify list item datatypes.
Config file:
[section]
listKey1: 1001, 1002, 1003
listKey2: AAAA, BBBB, CCCC
Code:
cfgFile = 'config.ini'
parser = ConfigParser(converters={'list': lambda x: [i.strip() for i in x.split(',')]})
parser.read(cfgFile)
list1 = list(map(int, parser.getlist('section', 'listKey1')))
list2 = list(map(str, parser.getlist('section', 'listKey2')))
print(list1)
print(list2)
Output:
[1001, 1002, 1003]
['AAAA', 'BBBB', 'CCCC']
If this is your config.ini:
[Section 3]
barList=item1,item2
Then with configparser you could do this:
from configparser import ConfigParser
config = ConfigParser()
config.read('config.ini')
my_list = config['Section 3']['barList'].split(',')
You will get:
my_list = ['item1', 'item2']
The split()-method will return a list, see Python string docs.
If you have white spaces in your config.ini like this:
[Section 3]
barList= item1, item2
Then you'd better do this:
my_list = [x.strip() for x in config['Section 3']['barList'].split(',')]
If your items are numbers (integers for instance), just apply:
my_list_of_ints = list(map(int, my_list))
You will get:
my_list_of_ints = [item1, item2]
I faced the same problem in the past. If you need more complex lists, consider creating your own parser by inheriting from ConfigParser. Then you would overwrite the get method with that:
def get(self, section, option):
""" Get a parameter
if the returning value is a list, convert string value to a python list"""
value = SafeConfigParser.get(self, section, option)
if (value[0] == "[") and (value[-1] == "]"):
return eval(value)
else:
return value
With this solution you will also be able to define dictionaries in your config file.
But be careful! This is not as safe: this means anyone could run code through your config file. If security is not an issue in your project, I would consider using directly python classes as config files. The following is much more powerful and expendable than a ConfigParser file:
class Section
bar = foo
class Section2
bar2 = baz
class Section3
barList=[ item1, item2 ]
import ConfigParser
import os
class Parser(object):
"""attributes may need additional manipulation"""
def __init__(self, section):
"""section to retun all options on, formatted as an object
transforms all comma-delimited options to lists
comma-delimited lists with colons are transformed to dicts
dicts will have values expressed as lists, no matter the length
"""
c = ConfigParser.RawConfigParser()
c.read(os.path.join(os.path.dirname(__file__), 'config.cfg'))
self.section_name = section
self.__dict__.update({k:v for k, v in c.items(section)})
#transform all ',' into lists, all ':' into dicts
for key, value in self.__dict__.items():
if value.find(':') > 0:
#dict
vals = value.split(',')
dicts = [{k:v} for k, v in [d.split(':') for d in vals]]
merged = {}
for d in dicts:
for k, v in d.items():
merged.setdefault(k, []).append(v)
self.__dict__[key] = merged
elif value.find(',') > 0:
#list
self.__dict__[key] = value.split(',')
So now my config.cfg file, which could look like this:
[server]
credentials=username:admin,password:$3<r3t
loggingdirs=/tmp/logs,~/logs,/var/lib/www/logs
timeoutwait=15
Can be parsed into fine-grained-enough objects for my small project.
>>> import config
>>> my_server = config.Parser('server')
>>> my_server.credentials
{'username': ['admin'], 'password', ['$3<r3t']}
>>> my_server.loggingdirs:
['/tmp/logs', '~/logs', '/var/lib/www/logs']
>>> my_server.timeoutwait
'15'
This is for very quick parsing of simple configs, you lose all ability to fetch ints, bools, and other types of output without either transforming the object returned from Parser, or re-doing the parsing job accomplished by the Parser class elsewhere.
json.loads & ast.literal_eval seems to be working but simple list within config is treating each character as byte so returning even square bracket....
meaning if config has fieldvalue = [1,2,3,4,5]
then config.read(*.cfg)
config['fieldValue'][0] returning [ in place of 1
As mentioned by Peter Smit (https://stackoverflow.com/a/11866695/7424596)
You might want to extend ConfigParser, in addition, an Interpolator can be used to automatically convert into and from the list.
For reference at the bottom you can find code which automatically converts config like:
[DEFAULT]
keys = [
Overall cost structure, Capacity, RAW MATERIALS,
BY-PRODUCT CREDITS, UTILITIES, PLANT GATE COST,
PROCESS DESCRIPTION, AT 50% CAPACITY, PRODUCTION COSTS,
INVESTMENT, US$ MILLION, PRODUCTION COSTS, US ¢/LB,
VARIABLE COSTS, PRODUCTION COSTS, MAINTENANCE MATERIALS
]
So if you request keys you will get:
<class 'list'>: ['Overall cost structure', 'Capacity', 'RAW MATERIALS', 'BY-PRODUCT CREDITS', 'UTILITIES', 'PLANT GATE COST', 'PROCESS DESCRIPTION', 'AT 50% CAPACITY', 'PRODUCTION COSTS', 'INVESTMENT', 'US$ MILLION', 'PRODUCTION COSTS', 'US ¢/LB', 'VARIABLE COSTS', 'PRODUCTION COSTS', 'MAINTENANCE MATERIALS']
Code:
class AdvancedInterpolator(Interpolation):
def before_get(self, parser, section, option, value, defaults):
is_list = re.search(parser.LIST_MATCHER, value)
if is_list:
return parser.getlist(section, option, raw=True)
return value
class AdvancedConfigParser(ConfigParser):
_DEFAULT_INTERPOLATION = AdvancedInterpolator()
LIST_SPLITTER = '\s*,\s*'
LIST_MATCHER = '^\[([\s\S]*)\]$'
def _to_list(self, str):
is_list = re.search(self.LIST_MATCHER, str)
if is_list:
return re.split(self.LIST_SPLITTER, is_list.group(1))
else:
return re.split(self.LIST_SPLITTER, str)
def getlist(self, section, option, conv=lambda x:x.strip(), *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self._get_conv(
section, option,
lambda value: [conv(x) for x in self._to_list(value)],
raw=raw,
vars=vars,
fallback=fallback,
**kwargs
)
def getlistint(self, section, option, *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self.getlist(section, option, int, raw=raw, vars=vars,
fallback=fallback, **kwargs)
def getlistfloat(self, section, option, *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self.getlist(section, option, float, raw=raw, vars=vars,
fallback=fallback, **kwargs)
def getlistboolean(self, section, option, *, raw=False, vars=None,
fallback=_UNSET, **kwargs):
return self.getlist(section, option, self._convert_to_boolean,
raw=raw, vars=vars, fallback=fallback, **kwargs)
Ps keep in mind importance of indentdation. As reads in ConfigParser doc string:
Values can span multiple lines, as long as they are indented deeper
than the first line of the value. Depending on the parser's mode, blank
lines may be treated as parts of multiline values or ignored.
you can use list in config file then parse it in python
from ast import literal_eval
literal_eval("[1,2,3,4]")
import json
json.loads("[1,2,3,4]")
and also you can use json file behind your config file like this:
your config file :
[A]
json_dis = .example.jason
--------------------
your code :
import configparser
config = configparser.ConfigParser()
config.read('config.ini')
# getting items of section A
config.items('A')
# result is a list of key-values
An improvement on split(',') might be to treat the comma separated values as a record in a CSV file
import csv
my_list = list(csv.reader([config['Section 3']['barList']], dialect=csv.excel))[0]
You can configure a dialect to parse whatever style of CSV you like.