fix edge case for dedent

HH-MWB · HH-MWB · commit 20f96f217831 · 2020-03-09T19:09:28.000-04:00
diff --git a/pandas/util/_decorators.py b/pandas/util/_decorators.py
@@ -284,7 +284,9 @@ def wrapper(*args, **kwargs) -> Callable:
         # formatting templates and concatenating docstring
         wrapper.__doc__ = "".join(
             [
-                arg.format(**kwargs) if isinstance(arg, str) else dedent(arg.__doc__)
+                arg.format(**kwargs)
+                if isinstance(arg, str)
+                else dedent(arg.__doc__ or "")
                 for arg in docstring_components
             ]
         )

Original file line number	Diff line number	Diff line change
`@@ -284,7 +284,9 @@ def wrapper(args, *kwargs) -> Callable:`
`284`	`284`	`# formatting templates and concatenating docstring`
`285`	`285`	`wrapper.__doc__ = "".join(`
`286`	`286`	`[`
`287`		`- arg.format(**kwargs) if isinstance(arg, str) else dedent(arg.__doc__)`
	`287`	`+ arg.format(**kwargs)`
	`288`	`+ if isinstance(arg, str)`
	`289`	`+ else dedent(arg.__doc__ or "")`
`288`	`290`	`for arg in docstring_components`
`289`	`291`	`]`
`290`	`292`	`)`