Adding and reading a config.ini file inside python package
Solution 1
There are two aspects to this question. First is the weird behavior of ConfigParser
. When ConfigParser
is unable to locate the .ini
file; it never gives, for some annoying reason, an IOError
or an error which indicates that it is unable to read the file.
In my case it keeps giving ConfigParser.NoSectionError
when the section
is clearly present. When I caught the ConfigParser.NoSectionError
error it gave an ImportError
! But it never tells you that it is simply unable to read the file.
Second is how to safely read the data files that are included in your package. The only way I found to do this was to use the __file__
parameter. This is how you would safely read the config.ini
in the above question, for Python27 and Python3:
import os
try:
# >3.2
from configparser import ConfigParser
except ImportError:
# python27
# Refer to the older SafeConfigParser as ConfigParser
from ConfigParser import SafeConfigParser as ConfigParser
config = ConfigParser()
# get the path to config.ini
config_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'config.ini')
# check if the path is to a valid file
if not os.path.isfile(config_path):
raise BadConfigError # not a standard python exception
config.read(config_path)
TEST_KEY = config.get('main', 'test_key') # value
This relies on the fact that config.ini
is located inside our package bootstrap
and is expected to be shipped with it.
The important bit is how you get the config_path
:
config_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'config.ini')
__file__
refers to the location of current script
that is being executed. In my question that means the location of stuff.py
, that is inside the bootstrap
folder, and so is config.ini
.
The above line of code then means; get the absolute path to stuff.py
; from that get path to the directory containing it; and join that with config.ini
(since it is in same directory) to give absolute path to the config.ini
. Then you can proceed to read it and raise an exception
just in case.
This will work even when you release your package on pip
and a user installs it from there.
As a bonus, and digressing from the question a bit, if you are releasing your package on pip
with data files inside your package, you must tell setuptools
to include them inside you package when you build sdist
and bdist
s. So to include the config.ini
in above package add the following lines to setup
class call in setup.py
:
include_package_data = True,
package_data = {
# If any package contains *.ini files, include them
'': ['*.ini'],
},
But it still may not work in some cases eg. building wheels etc. So you also do the same in your MANIFEST.IN
file:
include LICENSE
include bootstrap/*.ini
Solution 2
abhimanyuPathania : The issue is with path of config.ini
in stuff.py
. Change config.read('config.ini')
to config.read('./bootstrap/config.ini')
in stuff.py
. I tried the solution. It works for me.
Enjoying Pythoning...
Abhimanyu Pathania
building applications that do ~something~ Some of apps that I wrote: Thought Share - A simple social network where users can build groups and exchange ideas. lyrico - A python package that lets you batch download and tag lyrics for songs. JavaScript Algorithms - JavaScript implementation of popular computer science algorithms which you can run in your browser. linkiful - Save, tag, filter, search and backup your links. And there is much more. All the code is shared on my GitHub profile
Updated on June 21, 2022Comments
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Abhimanyu Pathania almost 2 years
I am writing my first python package which I want to upload on PyPI. I structured my code based on this blog post.
I want to store user setting in a config.ini file. Read it once(every time the package is run) in separate python module in same package and save user setting in global variables of that module. Later import those in other modules.
To recreate the error I just edited few lines of code, in the template described in the blog post. (Please refer to it since it would take too much typing to recreate entire thing here in question.)
The only difference is that my
stuff.py
reads from config file like this:from ConfigParser import SafeConfigParser config = SafeConfigParser() config.read('config.ini') TEST_KEY = config.get('main', 'test_key')
Here are the contents of
config.ini
(placed in same dir asstuff.py
):[main] test_key=value
And my
bootstrap.py
just imports and print theTEST_KEY
from .stuff import TEST_KEY def main(): print(TEST_KEY)
But on executing the package, the import fails give this error
Traceback (most recent call last): File "D:\Coding\bootstrap\bootstrap-runner.py", line 8, in <module> from bootstrap.bootstrap import main File "D:\Coding\bootstrap\bootstrap\bootstrap.py", line 11, in <module> from .stuff import TEST_KEY File "D:\Coding\bootstrap\bootstrap\stuff.py", line 14, in <module> TEST_KEY = config.get('main', 'test_key') File "C:\Python27\Lib\ConfigParser.py", line 607, in get raise NoSectionError(section) ConfigParser.NoSectionError: No section: 'main'
Import keeps giving ConfigParser.NoSectionError, but if you build/run only stuff.py(I use sublime3), the module gives no errors and printing
TEST_KEY
givesvalue
as output.Also, this method of import does work when I just use 3 files(config, stuff, main) in a dir and just execute the main as a script. But there I had to import it like this
from stuff import TEST_KEY
I'm just using the explicit relative imports as described in that post but don't have enough understanding of those. I guess the error is due to project structure and import, since running
stuff.py
as standalone script raises noConfigParser.NoSectionError
.Other method to read the config file once and then use data in other modules will be really helpful as well.
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Paul Cornelius about 8 yearsI'm not sure if this is your problem, but the ConfigParser.read() function does not raise an Exception if the file can't be found or there is some kind of IO error (see the docs). If it can't read the file, it will fail silently and just initialize to an empty dictionary,
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Abhimanyu Pathania about 8 years@PaulCornelius But if you run the stuff.py alone it does read the ini file and gives not errors. Only when I'm importing TEST_KEY like that, it raises that error.
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Paul Cornelius about 8 yearsThat's my point. I thought it might be useful to isolate the reason why the program is failing, which you can do by inspecting the returned value from ConfigParser.read(). I can't follow what you're saying about standalone versus import versus files, etc. I don't know what you mean by "when I execute the package."
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Abhimanyu Pathania about 8 yearsyes it does work. But now if I build stuff.py standalone, it gives the same error. So issue is definitely with the path. Can you please edit your answer and explain a bit more?
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Srikanth Lankapalli about 8 yearsSure... What steps are you doing to build in stand alone and how are you executing them... Please elaborate
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Abhimanyu Pathania about 8 yearsBy build I mean just open stuff.py in sublime and (Ctrl + B) to run it. Or you can open cmd prompt, cd to inner bootstrap dir and then: python stuff.py
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Srikanth Lankapalli about 8 years@abhimanyuPathania The path is relative ..it depends on who is calling .... if you are executing
python stuff.py
then it isconfig.ini
if you are executingpython -m bootstrap
then it is./bootstrap/config.ini
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Abhimanyu Pathania about 8 yearsok. Thanks. I will dig a bit more into relative and absolute paths and will mark your answer as accepted later.