Subclass string.Template instead

Author: seisman

pygmt/helpers/decorators.py

@@ -6,6 +6,7 @@
 """
 
 import functools
+import string
 import textwrap
 import warnings
 from inspect import Parameter, signature
@@ -442,6 +443,13 @@ def fmt_docstring(module_func):
     <BLANKLINE>
     """  # noqa: D410,D411
 
+    class _MyTemplate(string.Template):
+        """
+        A Template subclass that allows missing placeholders in docstrings.
+        """
+
+        delimiter = ""
+
     class _Placeholder(dict):
         """
         A dict subclass that allows missing placeholders in docstrings.
@@ -455,8 +463,7 @@ def __missing__(self, key):
             """
             return "{" + key + "}"
 
-    filler_text = _Placeholder()
-
+    filler_text = {}
     if hasattr(module_func, "aliases"):
         aliases = ["**Aliases:**\n"]
         aliases.append(".. hlist::")
@@ -481,7 +488,7 @@ def __missing__(self, key):
     # Dedent the docstring to make it all match the option text.
     docstring = textwrap.dedent(module_func.__doc__)
 
-    module_func.__doc__ = docstring.format_map(filler_text)
+    module_func.__doc__ = _MyTemplate(docstring).safe_substitute(**filler_text)
     return module_func