import os
dir = os.getcwd()
subdir = os.listdir(dir)
for i in subdir:
path = os.path.join(dir, i)
if os.path.isdir(path):
end_dir = os.listdir(path)
for i in range(len(end_dir)):
newname = end_dir[i][0:50]
os.rename(os.path.join(path, end_dir[
i]), os.path.join(path, newname))
