Fix BUG: Exception when PYTHONOPTIMIZE=2

python/cudf/cudf/core/dataframe.py

@@ -7528,10 +7528,11 @@ def merge(left, right, *args, **kwargs):
 
 # a bit of fanciness to inject docstring with left parameter
 merge_doc = DataFrame.merge.__doc__
-idx = merge_doc.find("right")
-merge.__doc__ = "".join(
-    [merge_doc[:idx], "\n\tleft : DataFrame\n\t", merge_doc[idx:]]
-)
+if merge_doc is not None:
+    idx = merge_doc.find("right")
+    merge.__doc__ = "".join(
+        [merge_doc[:idx], "\n\tleft : DataFrame\n\t", merge_doc[idx:]]
+    )
 
 
 def _align_indices(lhs, rhs):

python/cudf/cudf/utils/docutils.py

@@ -27,23 +27,24 @@ def docfmt(**kwargs):
 
     def outer(fn):
         buf = []
-        formatsiter = string.Formatter().parse(fn.__doc__)
-        for literal, field, fmtspec, conv in formatsiter:
-            assert conv is None
-            assert not fmtspec
-            buf.append(literal)
-            if field is not None:
-                # get indentation
-                lines = literal.rsplit("\n", 1)
-                if _only_spaces(lines[-1]):
-                    indent = " " * len(lines[-1])
-                    valuelines = kwargs[field].splitlines(True)
-                    # first line
-                    buf.append(valuelines[0])
-                    # subsequent lines are indented
-                    buf.extend([indent + ln for ln in valuelines[1:]])
-                else:
-                    buf.append(kwargs[field])
+        if fn.__doc__ is not None:
+            formatsiter = string.Formatter().parse(fn.__doc__)
+            for literal, field, fmtspec, conv in formatsiter:
+                assert conv is None
+                assert not fmtspec
+                buf.append(literal)
+                if field is not None:
+                    # get indentation
+                    lines = literal.rsplit("\n", 1)
+                    if _only_spaces(lines[-1]):
+                        indent = " " * len(lines[-1])
+                        valuelines = kwargs[field].splitlines(True)
+                        # first line
+                        buf.append(valuelines[0])
+                        # subsequent lines are indented
+                        buf.extend([indent + ln for ln in valuelines[1:]])
+                    else:
+                        buf.append(kwargs[field])
 
         fn.__doc__ = "".join(buf)
         return fn