simple way to find package name

find-package.el

;;; autopyimport.el --- Import python packages automatically


;; Copyright(C) 2017 CAPG Lab., Zhejiang University.


;; Author: Z. Wang <[email protected]>
;; Version: 1.0
;; Package-Requires: (())
;; Keywords: python, import
;; URL: http://blog.mightu.cc/autopyimport

;;; Commentary:

;; This package is used to fix (simply) python auto import.el


(defvar packageregex "\\([A-Za-z0-9]+\\)\\.")

(defun find-imports (buffer-content)
  (let ((start-position 0) (candidates nil))
    (while (string-match packageregex buffer-content start-position)
      (let* ((package-name-start (nth 2 (match-data)))
             (package-name-end (nth 3 (match-data)))
             (next-start (match-end 0))
             (potential-name (substring buffer-content package-name-start package-name-end)))
        (unless (or (assoc potential-name candidates)
                    (string-match potential-name (substring buffer-content 0 package-name-start)))
          (push (cons potential-name package-name-start)
                candidates))
        (setq start-position next-start)))
    candidates))

(defun fix-imports (buffer)
  (interactive "bfile to fix:")
  (with-current-buffer buffer
    (message "%s" (find-imports (buffer-string))))
  )

(provide 'fix-imports)

thanks, @jlf.