Configparser: parsing error with missing values

Question

Configparser: parsing error with missing values

I am using Python old fashioned configparser

module to read config files from filesystem.

To check if the custom config file is using the correct syntax, I compare all section keys and subsections to a referenced config file ref_config.ini

that contains all allowed section keys and subkeys with committed values.

Parsing a custom file doesn't really matter and works pretty well. However, reading the reference-config results in the ParsingError

following:

ParsingError: Source contains parsing errors: 'ref_config.ini'
    [line  2]: 'rotations_to_simulate\n'
    [line  3]: 'number_of_segments\n'
    [line  4]: 'material_data\n'
    [line  7]: 'rpm\n'

The file ref_config.ini

contains the following lines:

[GENERAL DATA]
rotations_to_simulate
number_of_segments
material_data

[TECHNICAL DATA]
rpm

To read the above config file I am using the following code:

#!/usr/bin/env python3
# coding: utf-8

import configparser
import os.path

def read_ref_config():
    config = configparser.ConfigParser()
    if not os.path.isfile('ref_config.ini'):
        return False, None
    else:
        config.read('ref_config.ini')
        return True, config

However, ommiting values in the config file should not raise a ParsingError as the docs says:

Values can be omitted, in which case the key / value separator can also be omitted.

[No Values]
key_without_value
empty string value here =

Update:

I just copied and pasted the contents of the given example from the docs into my file ref_config.ini

and got a similar ParsingError with NoValue keys containing no spaces:

ParsingError: Source contains parsing errors: 'ref_config.ini'
    [line 20]: 'key_without_value\n'

+3

python parsing configuration-files configparser

albert June 24. 15 at 14:47

source to share

1 answer

LittleQ · Accepted Answer · 2015-06-24T15:09:35+0000

Simple way:

configparser.ConfigParser(allow_no_value=True)

according to configparse docs

>>> import configparser

>>> sample_config = """
... [mysqld]
...   user = mysql
...   pid-file = /var/run/mysqld/mysqld.pid
...   skip-external-locking
...   old_passwords = 1
...   skip-bdb
...   # we don't need ACID today
...   skip-innodb
... """
>>> config = configparser.ConfigParser(allow_no_value=True)
>>> config.read_string(sample_config)

>>> # Settings with values are treated as before:
>>> config["mysqld"]["user"]
'mysql'

>>> # Settings without values provide None:
>>> config["mysqld"]["skip-bdb"]

>>> # Settings which aren't specified still raise an error:
>>> config["mysqld"]["does-not-exist"]
Traceback (most recent call last):
  ...
KeyError: 'does-not-exist'

Configparser: parsing error with missing values

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