import re
rx = r"\./([^\W_]+)_word1_([0-9.]+)_([0-9.]+)_([0-9]+(?:\.[0-9]+)*)"
s = "./test1_word1_1.1_1.2_1.3.csv"
m = re.search(rx, s)
if m:
print("Part1: {}\nPart2: {}\nPart3: {}\nPart4: {}".format(m.group(1), m.group(2), m.group(3), m.group(4) ))
aW1wb3J0IHJlCnJ4ID0gciJcLi8oW15cV19dKylfd29yZDFfKFswLTkuXSspXyhbMC05Ll0rKV8oWzAtOV0rKD86XC5bMC05XSspKikiCnMgPSAiLi90ZXN0MV93b3JkMV8xLjFfMS4yXzEuMy5jc3YiCm0gPSByZS5zZWFyY2gocngsIHMpCmlmIG06CglwcmludCgiUGFydDE6IHt9XG5QYXJ0Mjoge31cblBhcnQzOiB7fVxuUGFydDQ6IHt9Ii5mb3JtYXQobS5ncm91cCgxKSwgbS5ncm91cCgyKSwgbS5ncm91cCgzKSwgbS5ncm91cCg0KSApKQ==