Multiple dictionaries (add default one) for dictionary config setting

[yarikoptic]

we have

❯ grep dictionary .codespellrc
dictionary = .codespell_dict

in https://github.com/bids-standard/bids-specification/blob/HEAD/.codespellrc but that disables default dictionaries, and I need to specify -D- to get them used:

❯ codespell
❯ codespell -D-
./DECISION-MAKING.md:17: Curent ==> Current
./src/common-principles.md:188: entites ==> entities

Unfortunately, -D is the different style than e.g. --skip which expects them comma separated and -D doesn't work that way:

❯ git diff
diff --git a/.codespellrc b/.codespellrc
index 28aeafee..a513a1a7 100644
--- a/.codespellrc
+++ b/.codespellrc
@@ -2,5 +2,5 @@
 skip = *.js,*.svg,*.eps,.git
 ignore-words-list = fo,te,als
 builtin = clear,rare
-dictionary = .codespell_dict
+dictionary = -,.codespell_dict
 exclude-file = src/CHANGES.md
❯ codespell
...
codespell: error: argument -D/--dictionary: expected one argument

so the question is how could I keep using default dictionaries + custom one while relying on specification in the config file?

[DimitriPapadopoulos]

Let's start with command line options, we'll look into configuration files later. The output of --help reads:

  -D DICTIONARY, --dictionary DICTIONARY
                        custom dictionary file that contains spelling corrections. If this flag is not specified or equals "-"
                        then the default dictionary is used. This option can be specified multiple times.

I would expect -D - -D .codespell_dict to work. Can you check it does?

If it does work, chances are this works in the configuration file:

dictionary = -
dictionary = .codespell_dict

[yarikoptic]

Thank you @DimitriPapadopoulos for the rapid follow up -- sorry I missed it .

-D- -D .codespell_dict -- works!

❯ codespell -D- -D .codespell_dict
./README.md:63: folders ==> directories
./README.md:64: sub-directory ==> subdirectory
./README.md:65: zumba ==> zebra
./DECISION-MAKING.md:17: Curent ==> Current
./src/common-principles.md:188: entites ==> entities
❯ codespell -D-
./DECISION-MAKING.md:17: Curent ==> Current
./src/common-principles.md:188: entites ==> entities
❯ cat .codespell_dict
sub-directory->subdirectory
sub-directories->subdirectories
file name->filename
file names->filenames
folder->directory
folders->directories
zumba->zebra

Two lines in config file -- does not!

❯ grep dictionary .codespellrc
dictionary = -
dictionary = .codespell_dict
changes on filesystem:                                                                                                                                       
 .codespellrc | 1 +
❯ codespell --version
2.2.2
changes on filesystem:                                                                                                                                       
 .codespellrc | 1 +
❯ codespell
Traceback (most recent call last):
  File "/usr/bin/codespell", line 33, in <module>
    sys.exit(load_entry_point('codespell==0.0.0', 'console_scripts', 'codespell')())
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/codespell_lib/_codespell.py", line 767, in _script_main
    return main(*sys.argv[1:])
           ^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/codespell_lib/_codespell.py", line 772, in main
    options, parser = parse_options(args)
                      ^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/codespell_lib/_codespell.py", line 427, in parse_options
    config.read(cfg_files)
  File "/usr/lib/python3.11/configparser.py", line 712, in read
    self._read(fp, filename)
  File "/usr/lib/python3.11/configparser.py", line 1111, in _read
    raise DuplicateOptionError(sectname, optname,
configparser.DuplicateOptionError: While reading from '.codespellrc' [line  6]: option 'dictionary' in section 'codespell' already exists

[DimitriPapadopoulos]

While configparser raises the DuplicationError, it also provides a strict option to customize parser behaviour:

• strict, default value: True
  When set to True, the parser will not allow for any section or option duplicates while reading from a single source (using read_file(), read_string() or read_dict()). It is recommended to use strict parsers in new applications.

Since this is not a new application, I shall propose to set strict to False, for consistency between commend line option -D and config file option dictionary.

We can think about adding support for multiple dictionaries separated by , in a later merge request.

[yarikoptic]

no good. With

the patch adding strict=False

diff --git a/codespell_lib/_codespell.py b/codespell_lib/_codespell.py
index a082e6d1..8f975179 100644
--- a/codespell_lib/_codespell.py
+++ b/codespell_lib/_codespell.py
@@ -541,7 +541,7 @@ def parse_options(
     cfg_files = ["setup.cfg", ".codespellrc"]
     if options.config:
         cfg_files.append(options.config)
-    config = configparser.ConfigParser(interpolation=None)
+    config = configparser.ConfigParser(interpolation=None, strict=False)
 
     # Read toml before other config files.
     toml_files = []
@@ -571,7 +571,7 @@ def parse_options(
     # Collect which config files are going to be used
     used_cfg_files = []
     for cfg_file in cfg_files:
-        _cfg = configparser.ConfigParser()
+        _cfg = configparser.ConfigParser(strict=False)
         _cfg.read(cfg_file)
         if _cfg.has_section("codespell"):
             used_cfg_files.append(cfg_file)

it no longer crashes but it just takes the 2nd value as the value, not a list of values (ie dictionaries).

[DimitriPapadopoulos]

Right, configparser.ConfigParser.read_file does not raise a DuplicateOptionError any more, but appears to be silently overwriting old values instead of creating a list of values. I cannot find a relevant option in Customizing Parser Behaviour, actually the documentation does not specify the behaviour at all.

I need to dig in configparser, but if the behaviour is not specified in the documentation, I suspect whatever solution I try will be fragile. See for example:

• ConfigParser Duplicate keys in python
• Python issue 12662: Add support for duplicate options in configparser

[DimitriPapadopoulos]

@larsoner I see multiple issues in codespell options:

1. Some command line options “can be specified multiple times” (-D/--dictionary), others expect “comma-separated list of files” (-S/--skip), others don't even bother to document how to specify multiple files (-I/--ignore-words and -x/--exclude-file), if possible at all.
2. In the case of -D/--dictionary, what works for command line options will not work in INI files: you cannot have multiple occurrences of the same key in INI files by default – or at least configparser will at best take the last value into account and discard previous values.

Solutions:

1. We could modify the behaviour of configparser to accept multiple occurrences of keys, using a custom dict_type for configparser.ConfigParser. This would result in non-standard INI files, but command line options that “can be specified multiple times” could be used the same way in a config file.
2. We could modify all the above options that accept a file to accept a “comma-separated list of files”. Then command line options and config file options could be equivalent.

We could do both, of course.

Thoughts?

[larsoner]

I prefer solution (2) to (1)

[DimitriPapadopoulos]

Solution 2 is being implemented in #2767.