批量修改文件扩展名

a_txt='txt'
b_csv='csv'
def get_list():
all_name=os.listdir(os.getcwd())
return all_name

def find_file():
file_name=[]
for i in get_list():
try:
if i.split('.')[1]==a_txt:
file_name.append(i)
except:
pass
return  file_name

def change_name():
for i in find_file():
os.renames(i,i.split('.')[0]+'.'+b_csv)
print(u'完成批量修改')

if __name__=='__main__':
change_name()