Request Headers

[lolyinseo]

According CURL doc https://curl.se/libcurl/c/CURLOPT_HTTPHEADER.html
All headers with empty value should be removed, without replacing with default headers

If you add a header with no content as in 'Accept:' (no data on the right side of the colon), the internally used header is disabled/removed. With this option you can add new headers, replace internal headers and remove internal headers. To add a header with no content (nothing to the right side of the colon), use the form 'name;' (note the ending semicolon).

But this will not happen. For example

{'Content-Type': ''}

In the request it becomes like

Content-Type:

Headers like

{'Content-Type': None}

Produces a huge number of errors(since you always expect a string)

If I removing the header completely the default Curl header appearing(As it should be according to the documentation).

Content-Type: application/x-www-form-urlencoded

suggest that the correct behavior for {'Some-Header': None} is remove headers ( set Some-Header: for curl), and for {'Some-Header': ''} is set Some-Header; (note the ending semicolon).

[perklet]

It makes sense to me. Anyway, can you describe a situation where you would want to completely make the Content-Type header removed in the request?

[lolyinseo]

It makes sense to me. Anyway, can you describe a situation where you would want to completely make the Content-Type header removed in the request?

not only Content-Type, this behavior should apply to all headers. In my case, the server only accepts requests with missing Content-Type

[PalmtopTiger]

Agree. Need a way to remove default headers by setting them to None.

Here's another example:
curl_cffi by default sends Sec-Fetch-User header with each request:
Sec-Fetch-User: ?1
This header signals that the request was initiated by user. According to the documentation, it can only have one value - "?1". Otherwise, this header should not be sent. For example, when requesting images or styles. Removing this header is necessary to pretend to be a browser.