Python不知道哪有问题，请看看

import time
scale=50
print("执行开始".center(scale//2,'-'))
t = time.clock()
for i in range(scale+1):
a='*'i
b='.'(scale-i)
c=(i/scale)*100
t-=time.clock()
print('\r{:^3.0f}%[{}->{}]{:.2f}s'.format(c,a,b,-t),end='')
time.sleep(0.5)
print("\n"+"执行结束".center(scale//2,"-"))

import time
scale=50
print("执行开始".center(scale//2,'-'))
t = time.time()
for i in range(scale+1):
    a='*' * i
    b='.' * (scale-i)
    c=(i/scale)*100
    d =time.time() - t
    print('\r{:^3.0f}%[{}->{}]   {:.2f}s'.format(c,a,b,d),end='')
    time.sleep(0.5)
print("\n"+"执行结束".center(scale//2,"-"))