It's not a pure CoPilot alternative, but I'd put https://codesearch.ai into the mix (disclaimer, it's my side project).
It is a semantic code search tool that can be queried using natural language. It provides decent answers to a variety of questions, and I've been finding myself using it quite often to "autocomplete" various mundane tasks. For example, plotting with matplotlib, making http requests in Go, running multiple goroutines, etc. - things where I would usually reach for Google. It doesn't provide a straightforward ready-to-run answer like CoPilot, but it does provide a way to help yourself. It all depends on what you prefer and how you learn. Arguably, having to read the code before you use it makes it more likely it will stick in your brain.
It is a semantic code search tool that can be queried using natural language. It provides decent answers to a variety of questions, and I've been finding myself using it quite often to "autocomplete" various mundane tasks. For example, plotting with matplotlib, making http requests in Go, running multiple goroutines, etc. - things where I would usually reach for Google. It doesn't provide a straightforward ready-to-run answer like CoPilot, but it does provide a way to help yourself. It all depends on what you prefer and how you learn. Arguably, having to read the code before you use it makes it more likely it will stick in your brain.