rename_per_10000.py

import os
for i in range(37, 39):
    old = '641C%04d.JPG' % i
    old1 = '641C%04d.CR2' % i
    new = '641D%04d.JPG' % i
    new1 = '641D%04d.CR2' % i
    print('move %s to %s' % (old, new))
    os.rename(old, new)
    print('move %s to %s' % (old1, new1))
    os.rename(old1, new1)