当我们要对数值进行格式化输出时，可以使用Python内置的format函数，其功能强大，使用方便。代码示例如下：

x=1234.56789
print(format(x,'0.2f'))
print(format(x,'>10.1f'))
print(format(x,'<10.1f'),"|")
print(format(x,'^10.1f'),'|')
print(format(x,','))
print(format(x,'0,.1f'))
print(format(x,'e'))
print(format(x,'0.2E'))
y='The value is {:0,.2f}'.format(x)
print(y)

参考资料：

https://docs.python.org/3/library/functions.html#format

https://docs.python.org/3/library/string.html#formatspec