Fix #2019: Escape pipe characters in CSV-to-Markdown table conversion

[dry-shy]

Summary

Fixes #2019 by escaping pipe (|) characters in CSV cell values before generating Markdown tables.

Problem

Markdown tables use the pipe character (|) as a column separator. When CSV cell values contain unescaped pipe characters, the generated Markdown table becomes malformed and renders incorrectly in GitHub Flavored Markdown.

Example CSV:

Name,Value
A,x|y

Current output:

| Name | Value |
| --- | --- |
| A | x|y |

This causes the table structure to break because x|y is interpreted as multiple columns.

Solution

Added a helper function to escape pipe characters in header and data cells before rendering Markdown rows:

def _escape_cell(value: str) -> str:
    return str(value).replace("|", r"\|")

All table cells are now processed through _escape_cell() before being added to the Markdown output.

Result

Generated Markdown:

| Name | Value |
| --- | --- |
| A | x\|y |

The table now renders correctly even when cell values contain pipe characters.

Testing

Added/updated tests to verify that:

• Pipe characters in header cells are escaped.
• Pipe characters in data cells are escaped.
• Generated Markdown tables render correctly in GitHub Flavored Markdown.

Related Issue

Fixes #2019

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