DOC: Clarify nrows behavior in read_csv

[johnyu013]

• closes DOC: clarify how read_csv nrows interacts with header and skiprows argument #59078
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

Here’s the updated summary with a note section included:

Summary:

This pull request updates the nrows parameter documentation for read_csv to address ambiguity in the previous text. The original documentation was vague and did not clearly specify that nrows counts only the data rows returned, excluding the header, and skipped rows. The revised documentation provides a clearer definition of nrows and includes practical examples to better illustrate its usage, improving the overall clarity of the documentation.

Note:

Thanks to the suggestions from a previous PR made by the issuer and insights from Stack Overflow (https://stackoverflow.com/questions/23853553/python-pandas-how-to-read-only-first-n-rows-of-csv-files-in), the updated documentation hopefully clarifies that nrows excludes rows skipped with skiprows, and the header row. Please let me know if any examples should be added, revised, or removed to further enhance clarity. I understand that the example with skiprows might seem obvious, but it was included to address potential confusion.

[mroeschke]

Thanks @johnyu013