From 08d906aed202ae5f5cba18bcdac8c4e3f94d831d Mon Sep 17 00:00:00 2001
From: Ingmar Schoegl <ischoegl@lsu.edu>
Date: Fri, 11 Aug 2023 06:13:16 -0500
Subject: [PATCH] Facilitate argparse documentation

---
 interfaces/cython/cantera/cti2yaml.py  | 12 ++++++++++--
 interfaces/cython/cantera/ctml2yaml.py | 13 +++++++++++--
 interfaces/cython/cantera/yaml2ck.py   | 16 +++++++++++-----
 3 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/interfaces/cython/cantera/cti2yaml.py b/interfaces/cython/cantera/cti2yaml.py
index 1963be042..a42b2142b 100644
--- a/interfaces/cython/cantera/cti2yaml.py
+++ b/interfaces/cython/cantera/cti2yaml.py
@@ -1720,8 +1720,10 @@ def convert(filename=None, output_name=None, text=None, encoding="latin-1"):
     return len(_species), len(_reactions), surfaces, output_name
 
 
-def main():
-    """Parse command line arguments and pass them to `convert`."""
+def create_argparser():
+    """
+    Create argparse parser
+    """
     parser = argparse.ArgumentParser(
         description=(
             "Convert legacy CTI input files to YAML format, where the first contiguous "
@@ -1743,6 +1745,12 @@ def main():
         "--no-validate", action="store_true", default=False,
         help="Skip validation step.")
 
+    return parser
+
+
+def main():
+    """Parse command line arguments and pass them to `convert`."""
+    parser = create_argparser()
     if len(sys.argv) not in [2, 3, 4, 5]:
         if len(sys.argv) > 5:
             print(
diff --git a/interfaces/cython/cantera/ctml2yaml.py b/interfaces/cython/cantera/ctml2yaml.py
index 2ab763680..556141bda 100644
--- a/interfaces/cython/cantera/ctml2yaml.py
+++ b/interfaces/cython/cantera/ctml2yaml.py
@@ -2652,8 +2652,10 @@ def convert(
             emitter.dump(output_reactions, output_file)
 
 
-def main():
-    """Parse command line arguments and pass them to `convert`."""
+def create_argparser():
+    """
+    Create argparse parser
+    """
     parser = argparse.ArgumentParser(
         description="Convert legacy CTML input files to YAML format",
         epilog=(
@@ -2664,6 +2666,13 @@ def main():
     )
     parser.add_argument("input", help="The input CTML filename. Must be specified.")
     parser.add_argument("output", nargs="?", help="The output YAML filename. Optional.")
+
+    return parser
+
+
+def main():
+    """Parse command line arguments and pass them to `convert`."""
+    parser = create_argparser()
     if len(sys.argv) not in [2, 3]:
         if len(sys.argv) > 3:
             print(
diff --git a/interfaces/cython/cantera/yaml2ck.py b/interfaces/cython/cantera/yaml2ck.py
index a21f8d0e4..adf26f3d7 100644
--- a/interfaces/cython/cantera/yaml2ck.py
+++ b/interfaces/cython/cantera/yaml2ck.py
@@ -717,13 +717,10 @@ def convert(
     return output_files
 
 
-def main():
+def create_argparser():
     """
-    Parse command line arguments and pass them to `convert`
-
-    .. versionadded:: 3.0
+    Create argparse parser
     """
-
     parser = argparse.ArgumentParser(
         description="Convert Cantera YAML input files to Chemkin-format mechanisms",
     )
@@ -795,7 +792,16 @@ def main():
         default=True,
         help="Check that the mechanism can be loaded back into Cantera.",
     )
+    return parser
 
+
+def main():
+    """
+    Parse command line arguments and pass them to `convert`
+
+    .. versionadded:: 3.0
+    """
+    parser = create_argparser()
     args = parser.parse_args()
 
     output_paths = convert(