import os
def find_file(work_dir,extension='jpg'):
lst=[]
for filename in os.listdir(work_dir):
print(filename)
splits=os.path.splitext(filename)
ext=splits[1] #拿到扩展名
if ext=='.'+extension:
lst.append(filename)
return lst
r=find_file('.','py')
print(r) #返回所有目录下的md文件