I am going to implement a python client that search videos on youtube with different queries. Apparently I should use youtube data api for this. Even though I read quata cost I just want to be sure that using youtube api is totally free of charge. Sorry it is too basic.
Yes, using the YouTube API does not incur any monetary cost for the entity calling the API. If you go over your quota an 403 Error will be returned by the API.
Links:
YouTube API Quota Details
YouTube Quota Calculator
Google already provides a Python client for all of its APIs, including YouTube, which handles authentication, forming and making the API request as well as some datatype translation (i.e. JSON to dictionary, etc.). (link)