Excel Suddeny Displays Leading Quotes/Apostrophes in CSV Files: Apostrophe Trick No Longer Recommended by Microsoft
Generating CSV files that are opened using Excel can sometimes lead to unexpected results such as leading quotes or apostrophes appearing before text values. This article will explain the causes of this issue, the historic workaround using the "apostrophe trick," and why Microsoft no longer recommends this approach.
Understanding the Sudden Appearance of Leading Quotes/Apostrophes in CSV Files
The cause of this issue is rooted in the difference between how Excel and other applications interpret and display text values. Excel assumes text values are enclosed in double quotes, but if the text value itself contains a double quote, Excel will enclose the entire value in single quotes and escape the internal double quote. However, if the text value starts with a single quote or apostrophe, Excel may intermittently display it without any leading characters.
The Historic "Apostrophe Trick" Workaround
To deal with this issue, many developers have historically used what is known as the "apostrophe trick." This technique involves prefixing all text values in the CSV file with an apostrophe or single quote. Excel would then remove the leading apostrophe and display the text value without any leading characters. However, this workaround has some drawbacks that have led Microsoft to deprecate its use.
Why Microsoft No Longer Recommends the Apostrophe Trick
Microsoft no longer recommends using the apostrophe trick due to the following reasons:
- Limited compatibility: The apostrophe trick only works with some versions of Excel and may not work with other spreadsheet applications.
- Inconsistent behavior: As mentioned earlier, Excel may display text values without the leading apostrophe intermittently, resulting in inconsistent behavior.
- Data validation issues: Adding a leading apostrophe to a cell value may cause data validation issues when working with formulas in Excel.
Best Practices for Formatting CSV Files for Excel
Instead of using the apostrophe trick, consider the following best practices when formatting CSV files for Excel:
- Use double quotes to enclose all text values in the CSV file.
- Escape any internal double quotes within the text value using a backslash (\) or another delimiter character.
- Ensure the CSV file uses a consistent delimiter character, such as a comma or semicolon.
References
For further reading, consider the following resources:
- O'Reilly - Excel 2019 Power Programming with VBA
- Microsoft Support - Import or export text (.txt) or CSV files
- Stack Overflow - CSV file with apostrophes exported from Excel 2007 gets corrupted when opened