{"id":2220,"date":"2026-08-01T15:52:04","date_gmt":"2026-08-01T07:52:04","guid":{"rendered":"https:\/\/xlwings.net\/blog\/?p=2220"},"modified":"2026-03-28T11:19:50","modified_gmt":"2026-03-28T11:19:50","slug":"how-to-use-applicationwarnonfunctionnameconflict-in-the-xlwings-api-way","status":"publish","type":"post","link":"https:\/\/xlwings.net\/blog\/how-to-use-applicationwarnonfunctionnameconflict-in-the-xlwings-api-way\/","title":{"rendered":"How to use Application.WarnOnFunctionNameConflict in the xlwings API way"},"content":{"rendered":"\n

The WarnOnFunctionNameConflict<\/code> property of the Excel Application<\/code> object is a setting that controls whether Excel displays a warning message when a user-defined function (UDF) in an add-in has the same name as a built-in Excel function. This is particularly relevant when working with custom functions created via VBA or other add-ins, as name conflicts can cause confusion or unexpected behavior. In xlwings, you can access and modify this property to manage how Excel handles such conflicts, ensuring a smoother integration of custom functionality.<\/p>\n\n\n\n

Functionality:<\/strong>
When set to True<\/code>, Excel will show a warning dialog if a function name conflict is detected. This alert informs the user that a custom function may override or be confused with a built-in one, allowing them to decide how to proceed. When set to False<\/code>, no warning is issued, which can be useful in controlled environments where conflicts are intentional or managed. This property helps maintain clarity and prevent errors in spreadsheet calculations.<\/p>\n\n\n\n

Syntax in xlwings:<\/strong>
In xlwings, you interact with this property through the app<\/code> object, which represents the Excel application. The property is accessed as follows:<\/p>\n\n\n\n

import xlwings as xw\n\napp = xw.apps.active # Or xw.App() for a new instance\n# Get the current value\ncurrent_setting = app.api.WarnOnFunctionNameConflict\n# Set the value\napp.api.WarnOnFunctionNameConflict = True # or False<\/code><\/pre>\n\n\n\n
The app.api<\/code> provides direct access to the underlying Excel object model. The WarnOnFunctionNameConflict<\/code> property is a Boolean value:<\/p>\n\n\n\n
    \n
  • True<\/code>: Enables warnings for function name conflicts.<\/li>\n\n\n\n
  • False<\/code>: Disables warnings.<\/li>\n<\/ul>\n\n\n\n
    Example Usage:<\/strong>
    Suppose you are developing an add-in with custom functions and want to ensure users are alerted to potential conflicts. You can use xlwings to enable warnings dynamically. Below is a code example that checks the current setting, changes it to enable warnings, and then restores the original state after performing tasks.<\/p>\n\n\n\n
    import xlwings as xw\n\n# Connect to the active Excel application\napp = xw.apps.active\n\n# Store the original setting\noriginal_setting = app.api.WarnOnFunctionNameConflict\nprint(f\"Original WarnOnFunctionNameConflict setting: {original_setting}\")\n\n# Enable warnings for function name conflicts\napp.api.WarnOnFunctionNameConflict = True\nprint(\"Warnings enabled for function name conflicts.\")\n\n# Perform tasks that might involve custom functions, e.g., running a macro or adding an add-in\n# For demonstration, we just wait a moment\nimport time\ntime.sleep(2)\n\n# Restore the original setting\napp.api.WarnOnFunctionNameConflict = original_setting\nprint(f\"Restored WarnOnFunctionNameConflict to: {app.api.WarnOnFunctionNameConflict}\")<\/code><\/pre>\n\n\n\n
    <\/p>\n","protected":false},"excerpt":{"rendered":"
    The `WarnOnFunctionNameConflict` property of the Excel `Application` object is a setting that contro…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[],"class_list":["post-2220","post","type-post","status-publish","format-standard","hentry","category-xlwings-api-reference"],"_links":{"self":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts\/2220","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/comments?post=2220"}],"version-history":[{"count":2,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts\/2220\/revisions"}],"predecessor-version":[{"id":3394,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/posts\/2220\/revisions\/3394"}],"wp:attachment":[{"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/media?parent=2220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/categories?post=2220"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xlwings.net\/blog\/wp-json\/wp\/v2\/tags?post=2220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}