有时为了整洁统一或者要求，需要在数字前补足0到一定的位数，可使用zfill函数来操作，具体如下：

import configparser

conf = configparser.ConfigParser()
conf.read(r'E:\Projects\version.txt')
value_MainVersion = conf.get('Version', 'MainVersion')
value_SubVersion = conf.get('Version', 'SubVersion')
folder_name = "E:\Projects\test"
value_MainVersion = value_MainVersion.split('.')
for v in value_MainVersion:
    if len(v) == 1:
        v = v.zfill(2)
    folder_name += v
folder_name = folder_name + "_" + value_SubVersion
print(folder_name)

E:\Projects\test_022401_1