Textbook and workbook:
https://www.w3schools.com/python/default.asp
https://codingbat.com/python
Basic problem-solving
https://www.geeksforgeeks.org/python-programming-examples/
Hackerrank
https://www.hackerrank.com/domains/python?filters%5Bstatus%5D%5B%5D=unsolved&filters%5Bstatus%5D%5B%5D=solved&filters%5Bdifficulty%5D%5B%5D=easy&filters%5Bskills%5D%5B%5D=Python%20%28Basic%29&filters%5Bskills%5D%5B%5D=Problem%20Solving%20%28Basic%29&filters%5Bsubdomains%5D%5B%5D=py-strings&filters%5Bsubdomains%5D%5B%5D=py-introduction&filters%5Bsubdomains%5D%5B%5D=py-basic-data-types&filters%5Bsubdomains%5D%5B%5D=py-sets&badge_type=python
Reference and homework:
https://www.sololearn.com/learn/courses/python-introduction?location=2
https://www.sololearn.com/learning/1158
https://www.sololearn.com/learning/1159
practical problem practice
Code Quest Academy - https://lmcodequestacademy.com/quest (Easy problems only)
ACSL test 1 programs - http://titotit.com/xe/index.php?mid=ACSL&category=44255&document_srl=43638