Update avoid -> new in ExcelWriter if_sheet_exists

Author: mirober

pandas/io/excel/_base.py

@@ -666,11 +666,11 @@ class ExcelWriter(metaclass=abc.ABCMeta):
         be parsed by ``fsspec``, e.g., starting "s3://", "gcs://".
 
         .. versionadded:: 1.2.0
-    if_sheet_exists : {'avoid', 'replace', 'overwrite', 'fail'}, default 'avoid'
+    if_sheet_exists : {'new', 'replace', 'overwrite', 'fail'}, default 'new'
         How to behave when trying to write to a sheet that already
         exists (append mode only).
 
-        * avoid: Create a new sheet with a different name.
+        * new: Create a new sheet with a different name.
         * replace: Delete the contents of the sheet before writing to it.
         * overwrite: Write directly to the named sheet
           without deleting the previous contents.
@@ -880,17 +880,13 @@ def __init__(
 
         self.mode = mode
 
+        ise_valid = [None, "new", "replace", "overwrite", "fail"]
+        if if_sheet_exists not in ise_valid:
+            raise ValueError(f"'{if_sheet_exists}' is not valid for if_sheet_exists")
         if if_sheet_exists and "r+" not in mode:
             raise ValueError("if_sheet_exists is only valid in append mode (mode='a')")
-        if if_sheet_exists is not None and if_sheet_exists not in {
-            "avoid",
-            "replace",
-            "overwrite",
-            "fail",
-        }:
-            raise ValueError(f"'{if_sheet_exists}' is not valid for if_sheet_exists")
         if if_sheet_exists is None and "r+" in mode:
-            if_sheet_exists = "avoid"
+            if_sheet_exists = "new"
         self.if_sheet_exists = if_sheet_exists
 
     def __fspath__(self):

pandas/io/excel/_openpyxl.py

@@ -420,7 +420,7 @@ def write_cells(
 
         if sheet_name in self.sheets:
             if "r+" in self.mode:
-                if self.if_sheet_exists == "avoid":
+                if self.if_sheet_exists in "new":
                     wks = self.book.create_sheet()
                     # openpyxl will create a name for the new sheet by appending digits
                     wks.title = sheet_name

pandas/tests/io/excel/test_openpyxl.py

@@ -113,7 +113,7 @@ def test_write_append_mode(ext, mode, expected):
 @pytest.mark.parametrize(
     "if_sheet_exists,num_sheets,expected",
     [
-        ("avoid", 2, ["apple", "banana"]),
+        ("new", 2, ["apple", "banana"]),
         (None, 2, ["apple", "banana"]),
         ("replace", 1, ["pear"]),
         ("overwrite", 1, ["pear", "banana"]),
@@ -152,7 +152,7 @@ def test_if_sheet_exists_raises(ext):
 
     with tm.ensure_clean(ext) as f:
         with pytest.raises(ValueError, match=re.escape(mode_msg)):
-            ExcelWriter(f, engine="openpyxl", mode="w", if_sheet_exists="new_sheet")
+            ExcelWriter(f, engine="openpyxl", mode="w", if_sheet_exists="new")
 
     with tm.ensure_clean(ext) as f:
         with pytest.raises(ValueError, match=invalid_msg):

pandas/tests/io/excel/test_xlsxwriter.py

@@ -1,3 +1,4 @@
+import re
 import warnings
 
 import pytest
@@ -57,7 +58,10 @@ def test_column_format(ext):
 
 def test_write_append_mode_raises(ext):
     msg = "Append mode is not supported with xlsxwriter!"
+    ise_msg = "if_sheet_exists is only valid in append mode (mode='a')"
 
     with tm.ensure_clean(ext) as f:
         with pytest.raises(ValueError, match=msg):
             ExcelWriter(f, engine="xlsxwriter", mode="a")
+        with pytest.raises(ValueError, match=re.escape(ise_msg)):
+            ExcelWriter(f, engine="xlsxwriter", if_sheet_exists="replace")