python ljust,rjust,center,zfill对齐使用方法

字符串在输出时的对齐:
S.ljust(width,[fillchar]) 
#输出width个字符，S左对齐，不足部分用fillchar填充，默认的为空格。 
S.rjust(width,[fillchar]) #右对齐 
S.center(width, [fillchar]) #中间对齐 
S.zfill(width) #把S变成width长，并在右对齐，不足部分用0补足

实例

 >>> str = "this is string example....wow!!!";
 >>> str.ljust(50,'')
 'this is string example....wow!!!000000000000000000'
 >>> str.ljust(50)
 'this is string example....wow!!!                  '
 >>> str.rjust(50)
 '                  this is string example....wow!!!'
 >>> str.rjust(50,'')
 '000000000000000000this is string example....wow!!!'
 >>> str.center(50,'')
 '000000000this is string example....wow!!!000000000'
 >>> str.center(50)
 '         this is string example....wow!!!         '
 >>> str.zfill(50)
 '000000000000000000this is string example....wow!!!'
 >>>