feat(nvim): add python f-string transformer

Thanks to https://gist.github.com/linguini1/ee91b6d8c196cbd731d10a61447af6a3

dots/.config/nvim/after/ftplugin/python.lua

@@ -0,0 +1,31 @@
+-- Treesitter automatic Python format strings
+-- THANKS https://gist.github.com/linguini1/ee91b6d8c196cbd731d10a61447af6a3
+vim.api.nvim_create_augroup("py-fstring", { clear = true })
+vim.api.nvim_create_autocmd("InsertCharPre", {
+    pattern = { "*.py" },
+    group = "py-fstring",
+    --- @return nil
+    callback = function(opts)
+        -- Only run if f-string escape character is typed
+        if vim.v.char ~= "{" then return end
+
+        -- Get node and return early if not in a string
+        local node = vim.treesitter.get_node()
+
+        if not node then return end
+        if node:type() ~= "string" then node = node:parent() end
+        if not node or node:type() ~= "string" then return end
+
+        vim.print(node:type())
+        local row, col, _, _ = vim.treesitter.get_node_range(node)
+
+        -- Return early if string is already a format string
+        local first_char = vim.api.nvim_buf_get_text(opts.buf, row, col, row, col + 1, {})[1]
+        vim.print("row " .. row .. " col " .. col)
+        vim.print("char: '" .. first_char .. "'")
+        if first_char == "f" then return end
+
+        -- Otherwise, make the string a format string
+        vim.api.nvim_input("<Esc>m'" .. row + 1 .. "gg" .. col + 1 .. "|if<Esc>`'la")
+    end,
+})