355 specify toml dependency

README.md

@@ -16,8 +16,8 @@ Python's command line parsing modules such as argparse have very limited
 support for config files and environment variables, so this module
 extends argparse to add these features.
 
-**API docs:** https://bw2.github.io/ConfigArgParse/  
-  
+**API docs:** https://bw2.github.io/ConfigArgParse/
+
 **PyPI:** http://pypi.python.org/pypi/ConfigArgParse
 
 ## Install
@@ -158,14 +158,14 @@ Only command line args that have a long version (eg. one that starts with '--')
 can be set in a config file. For example, "--color" can be set by putting
 "color=green" in a config file. The config file syntax depends on the constructor
 arg: `config_file_parser_class` which can be set to one of the provided
-classes: 
+classes:
 - `DefaultConfigFileParser`
 - `YAMLConfigFileParser`
 - `ConfigparserConfigFileParser`
 - `IniConfigParser`
 - `TomlConfigParser`
 - `CompositeConfigParser`
-  
+
 or to your own subclass of the `ConfigFileParser` abstract class.
 
 #### *DefaultConfigFileParser* - the full range of valid syntax is:
@@ -332,6 +332,8 @@ parser = configargparse.ArgParser(
 
 [TOML](https://github.com/toml-lang/toml/blob/main/toml.md) parser. This config parser can be used to integrate with `pyproject.toml` files.
 
+Requires installation of [toml](https://pypi.org/project/toml/) for Python versions below 3.11.
+
 Example:
 
 ```toml
@@ -387,7 +389,7 @@ parser = configargparse.ArgParser(
 ...
 ```
 
-Note that it's required to put the TOML parser first because the INI syntax basically would accept anything whereas TOML.
+Note that it's required to put the TOML parser first because the INI syntax basically would accept anything whereas TOML is a bit more strict.
 
 ## ArgParser Singletons
 

configargparse.py

@@ -17,6 +17,7 @@
 import types
 from collections import OrderedDict
 import textwrap
+import warnings
 from io import StringIO
 
 ACTION_TYPES_THAT_DONT_NEED_A_VALUE = [
@@ -134,6 +135,10 @@ class ConfigFileParserException(Exception):
     """Raised when config file parsing failed."""
 
 
+class ConfigFileParserMissingDependency(Exception):
+    """Raised when an optional dependency is missing."""
+
+
 class DefaultConfigFileParser(ConfigFileParser):
     """
     Based on a simplified subset of INI and YAML formats. Here is the
@@ -316,7 +321,7 @@ def _load_yaml(self):
         try:
             import yaml
         except ImportError:
-            raise ConfigFileParserException(
+            raise ConfigFileParserMissingDependency(
                 "Could not import yaml. "
                 "It can be installed by running 'pip install PyYAML'"
             )
@@ -373,7 +378,7 @@ def serialize(self, items, default_flow_style=False):
 Provides `configargparse.ConfigFileParser` classes to parse ``TOML`` and ``INI`` files with **mandatory** support for sections.
 Useful to integrate configuration into project files like ``pyproject.toml`` or ``setup.cfg``.
 
-`TomlConfigParser` usage: 
+`TomlConfigParser` usage:
 
 >>> TomlParser = TomlConfigParser(['tool.my_super_tool']) # Simple TOML parser.
 >>> parser = ArgumentParser(..., default_config_files=['./pyproject.toml'], config_file_parser_class=TomlParser)
@@ -522,25 +527,25 @@ def parse(self, stream):
         """Parses the keys and values from a TOML config file."""
         # Use tomllib (Python 3.11+) if available, otherwise fall back to toml package
         try:
-            import tomllib
-
-            # tomllib.load() requires binary mode, so use loads() for stream compatibility
-            try:
-                content = stream.read()
-                # If content is bytes, decode it; if string, use as-is
-                if isinstance(content, bytes):
-                    content = content.decode("utf-8")
-                config = tomllib.loads(content)
-            except Exception as e:
-                raise ConfigFileParserException("Couldn't parse TOML file: %s" % e)
+            import tomllib as toml
         except ImportError:
-            # Fall back to toml package (supports text mode)
-            import toml
-
             try:
-                config = toml.load(stream)
-            except Exception as e:
-                raise ConfigFileParserException("Couldn't parse TOML file: %s" % e)
+                import toml
+            except ImportError as e:
+                raise ConfigFileParserMissingDependency(
+                    "Could not import toml or tomllib. "
+                    "toml can be installed by running 'pip install toml'"
+                ) from e
+
+        # tomllib.load() requires binary mode, so use loads() for stream compatibility
+        try:
+            content = stream.read()
+            # If content is bytes, decode it; if string, use as-is
+            if isinstance(content, bytes):
+                content = content.decode("utf-8")
+            config = toml.loads(content)
+        except Exception as e:
+            raise ConfigFileParserException("Couldn't parse TOML file: %s" % e)
 
         # convert to dict and filter based on section names
         result = OrderedDict()
@@ -577,7 +582,7 @@ def serialize(self, items):
         try:
             import toml
         except ImportError:
-            raise ConfigFileParserException(
+            raise ConfigFileParserMissingDependency(
                 "The 'toml' package is required for TOML serialization. "
                 "Install it with: pip install toml"
             )
@@ -764,7 +769,20 @@ class CompositeConfigParser(ConfigFileParser):
 
     def __init__(self, config_parser_types):
         super().__init__()
-        self.parsers = [p() for p in config_parser_types]
+        self.parsers: list[ConfigFileParser] = [p() for p in config_parser_types]
+
+        seen_ini = False
+        for parser in self.parsers:
+            if not seen_ini and isinstance(parser, IniConfigParser):
+                seen_ini = True
+                continue
+            if seen_ini and isinstance(parser, TomlConfigParser):
+                warnings.warn(
+                    "IniConfigParser was found before TomlConfigParser in parsers for "
+                    "CompositeConfigParser. This might lead to a TOML file being "
+                    "parsed as an INI file. Reorder the parsers.",
+                    category=SyntaxWarning,
+                )
 
     def __call__(self):
         return self
@@ -773,7 +791,12 @@ def parse(self, stream):
         errors = []
         for i, p in enumerate(self.parsers):
             try:
+                print(f"USING PARSER {p.__class__.__name__}")
                 return p.parse(stream)  # type: ignore[no-any-return]
+            except ConfigFileParserMissingDependency as e:
+                msg = f"Cannot use parser {p.__class__.__name__} without optional dependency."
+                print(msg)
+                raise
             except Exception as e:
                 errors.append(e)
                 # Try to seek back to beginning for next parser
@@ -804,7 +827,7 @@ def guess_format_name(classname):
 
         msg = "Uses multiple config parser settings (in order): \n"
         for i, parser in enumerate(self.parsers):
-            msg += f"[{i+1}] {guess_format_name(parser.__class__.__name__)}: {parser.get_syntax_description()} \n"
+            msg += f"[{i + 1}] {guess_format_name(parser.__class__.__name__)}: {parser.get_syntax_description()} \n"
         return msg
 
     def serialize(self, items):
@@ -1447,9 +1470,9 @@ def convert_item_to_command_line_arg(self, action, key, value):
         if action is not None and isinstance(
             action, ACTION_TYPES_THAT_DONT_NEED_A_VALUE
         ):
-            assert isinstance(
-                value, str
-            ), "config parser should convert anything that is not a list to string."
+            assert isinstance(value, str), (
+                "config parser should convert anything that is not a list to string."
+            )
             if value.lower() in ("true", "yes", "on", "1"):
                 if not is_boolean_optional_action(action):
                     args.append(command_line_key)
@@ -1725,7 +1748,7 @@ def format_help(self):
                 added_config_file_help = True
 
                 msg += (
-                    "Args that start with '%s' can also be set in " "a config file"
+                    "Args that start with '%s' can also be set in a config file"
                 ) % cc
                 config_arg_string = " or ".join(
                     a.option_strings[0] for a in config_path_actions if a.option_strings
@@ -1832,15 +1855,13 @@ def add_argument(self, *args, **kwargs):
     if action.is_positional_arg and env_var:
         raise ValueError("env_var can't be set for a positional arg.")
     if action.is_config_file_arg and not isinstance(action, argparse._StoreAction):
-        raise ValueError("arg with is_config_file_arg=True must have " "action='store'")
+        raise ValueError("arg with is_config_file_arg=True must have action='store'")
     if action.is_write_out_config_file_arg:
         error_prefix = "arg with is_write_out_config_file_arg=True "
         if not isinstance(action, argparse._StoreAction):
             raise ValueError(error_prefix + "must have action='store'")
         if is_config_file_arg:
-            raise ValueError(
-                error_prefix + "can't also have " "is_config_file_arg=True"
-            )
+            raise ValueError(error_prefix + "can't also have is_config_file_arg=True")
 
     return action
 

setup.py

@@ -46,8 +46,7 @@ def launch_http_server(directory):
             logging.debug("All network port. ")
     except Exception as e:
         logging.error(
-            "ERROR: while starting an HTTP server to serve "
-            "the coverage report: %s" % e
+            "ERROR: while starting an HTTP server to serve the coverage report: %s" % e
         )
 
 
@@ -82,7 +81,7 @@ def launch_http_server(directory):
 tests_require = [
     "black",
     "mock",
-    "toml",
+    "toml; python_version < '3.11'",
     "PyYAML",
     "pytest",
     "pytest-cov",
@@ -126,6 +125,7 @@ def launch_http_server(directory):
     install_requires=install_requires,
     tests_require=tests_require,
     extras_require={
+        "toml": ["toml; python_version < '3.11'"],
         "yaml": ["PyYAML"],
         "test": tests_require,
     },