str.format

#使用str.format()函数

#使用'{}'占位符
print('I\'m {},{}'.format('Hongten','Welcome to my space!'))
>>> I'm Hongten,Welcome to my space!
print('#' * 40)

#也可以使用'{0}','{1}'形式的占位符
print('{0},I\'m {1},my E-mail is {2}'.format('Hello','Hongten','hongtenzone@foxmail.com'))

>>> Hello,I'm Hongten,my E-mail is hongtenzone@foxmail.com

#可以改变占位符的位置
print('{1},I\'m {0},my E-mail is {2}'.format('Hongten','Hello','hongtenzone@foxmail.com'))
>>> Hello,I'm Hongten,my E-mail is hongtenzone@foxmail.com
print('#' * 40)
########################################
#使用'{name}'形式的占位符
print('Hi,{name},{message}'.format(name = 'Tom',message = 'How old are you?'))
>>> Hi,Tom,How old are you?
print('#' * 40)
########################################
#混合使用'{0}','{name}'形式
print('{0},I\'m {1},{message}'.format('Hello','Hongten',message = 'This is a test message!'))
>>> Hello,I'm Hongten,This is a test message!
print('#' * 40)
########################################
#下面进行格式控制
import math
print('The value of PI is approximately {}.'.format(math.pi))

>>> The value of PI is approximately 3.141592653589793.

print('The value of PI is approximately {!r}.'.format(math.pi))

>>> The value of PI is approximately 3.141592653589793.

print('The value of PI is approximately {0:.3f}.'.format(math.pi))
>>> The value of PI is approximately 3.142.

table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 7678}
for name, phone in table.items():
print('{0:10} ==> {1:10d}'.format(name, phone))
>>>
Dcab ==> 7678
Jack ==> 4098
Sjoerd ==> 4127

table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 8637678}
print('Jack: {0[Jack]:d}; Sjoerd: {0[Sjoerd]:d}; ''Dcab: {0[Dcab]:d}'.format(table))
>>> Jack: 4098; Sjoerd: 4127; Dcab: 8637678