Pass arguments to ConfigParser

README.rst

@@ -44,6 +44,12 @@ The command implementation reads the configuraion file(s) by using the
 ``ConfigFileProcessor.read_config()`` method and stores it in the
 ``default_map`` of the ``context_settings``.
 
+If you need to refine the behaviour of the underlying ConfigParser then pass
+named arguments to ``read_config``, these will be passed on to the
+ConfigParser constructor. e.g.
+
+``ConfigFileProcessor.read_config(interpolation=ExtendedInterpolation())``
+
 That is only the first part of the problem. We have now a solution that allows
 us to read configuration files (and override the command options defaults)
 before the command-line parsing begins.

click_configfile.py

@@ -382,10 +382,10 @@ def hello(ctx, name):
     # -- GENERIC PART:
     # Uses declarative specification from above (config_files, config_sections, ...)
     @classmethod
-    def read_config(cls):
+    def read_config(cls, **args):
         configfile_names = list(
             generate_configfile_names(cls.config_files, cls.config_searchpath))
-        parser = configparser.ConfigParser()
+        parser = configparser.ConfigParser(**args)
         parser.optionxform = str
         parser.read(configfile_names)
 

tests/functional/test_basics.py

@@ -301,7 +301,7 @@ class ConfigFileProcessorWithUnboundSection(ConfigFileProcessor2):
             # -- POINT: CONTEXT_SETTINGS = dict(default_map=...)
             ConfigFileProcessorWithUnboundSection.read_config()
 
-        expected = "LookupError: No schema found for: section=unbound.section"
+        expected = "No schema found for: section=unbound.section"
         assert expected in str(e)
 
 
@@ -378,3 +378,32 @@ def test_config_searchpath__param_from_primary_file_overrides_secondary(self,
         config = ConfigFileProcessor3.read_config()
         assert config == dict(name="Alice")
         assert config["name"] == "Alice"    # -- FROM: config_file1 (prefered)
+
+    # an example of passing extra parameters to the underlying ConfigParser
+    def test_inline_comments(self, cli_runner_isolated):
+        assert ConfigFileProcessor1.config_files[0] == "hello.ini"
+        CONFIG_FILE_CONTENTS1 = """
+            [default]
+            dummy = nothing
+            ; this is a comment
+            [hello]
+            name = Alice ; this is an inline comment
+            """
+        write_configfile_with_contents("hello.ini", CONFIG_FILE_CONTENTS1)
+        assert os.path.exists("hello.ini")
+        assert not os.path.exists("hello.cfg")
+
+        CONTEXT_SETTINGS = dict(
+            default_map=ConfigFileProcessor1.read_config(
+                    inline_comment_prefixes=[";", "#"]
+                )
+            )
+
+        @click.command(context_settings=CONTEXT_SETTINGS)
+        @click.pass_context
+        def hello(ctx):
+            click.echo("Hello %s" % ctx.default_map["name"])
+
+        result = cli_runner_isolated.invoke(hello, [])
+        assert result.output == "Hello Alice\n"
+        assert result.exit_code == 0

tests/unit/test_schema_description.py

@@ -162,5 +162,5 @@ def test_matches_section__with_bad_arg(self, bad_section_name):
             class Hello(SectionSchema):
                 pass
 
-        expected = "ValueError: %r (expected: string, strings)" % bad_section_name
+        expected = "%r (expected: string, strings)" % bad_section_name
         assert expected in str(e)