с использованием регулярных выражений
import re
test_str = ("___5weeks_rollingAverage_8hours", "___5weeks__rolling=*%Average_8hours",
"___5weeks_rollingAverage_8hours__", "___5weeks_rollingAverage_8hours")
regex = re.compile(r"[!\"#$%&'()*+,-.\/:;<=>?@\[\\\]^_`{|}~]{2,}")
for item in test_str:
item = regex.sub('', item)
print(item)
вывод
5weeks_rollingAverage_8hours
5weeksrollingAverage_8hours
5weeks_rollingAverage_8hours
5weeks_rollingAverage_8hours