Python ljust rjust center输出

看下面的例子就会明白了：

复制代码 代码如下:

print '|',''.ljust(10),'|'
print '|',''.ljust(10,'-'),'|'
print '|',''.rjust(10,'-'),'|'
print '|',''.center(10,'-'),'|'

for a in range(1, 6):
print 'a = '.ljust(5), repr(a).ljust(10), 'b = '.ljust(5), repr(a * 2)

输出结果:
| |
| --------- |
| --------- |
| --------- |
a = 1 b = 2
a = 2 b = 4
a = 3 b = 6
a = 4 b = 8
a = 5 b = 10