本文实例分析了python开发之str.format()用法。分享给大家供大家参考，具体如下：

格式化一个字符串的输出结果，我们在很多地方都可以看到，如：c/c++中都有见过

下面看看python中的字符串格式函数str.format():

#使用str.format()函数
#使用\'{}\'占位符
print(\'I\\\'m {},{}\'.format(\'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\'))
#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\'))
print(\'#\' * 40)
#使用\'{name}\'形式的占位符
print(\'Hi,{name},{message}\'.format(name = \'Tom\',message = \'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!\'))
print(\'#\' * 40)
#下面进行格式控制
import math
print(\'The value of PI is approximately {}.\'.format(math.pi))
print(\'The value of PI is approximately {!r}.\'.format(math.pi))
print(\'The value of PI is approximately {0:.3f}.\'.format(math.pi))
table = {\'Sjoerd\': 4127, \'Jack\': 4098, \'Dcab\': 7678}
for name, phone in table.items():
  print(\'{0:10} ==> {1:10d}\'.format(name, phone))
table = {\'Sjoerd\': 4127, \'Jack\': 4098, \'Dcab\': 8637678}
print(\'Jack: {0[Jack]:d}; Sjoerd: {0[Sjoerd]:d}; \'\'Dcab: {0[Dcab]:d}\'.format(table))

运行效果：

Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) [MSC v.1600 32 bit (Intel)] on win32
Type \"copyright\", \"credits\" or \"license()\" for more information.
>>> ================================ RESTART ================================
>>> 
I\'m Hongten,Welcome to my space!
########################################
Hello,I\'m Hongten,my E-mail is hongtenzone@foxmail.com
Hello,I\'m Hongten,my E-mail is hongtenzone@foxmail.com
########################################
Hi,Tom,How old are you?
########################################
Hello,I\'m Hongten,This is a test message!
########################################
The value of PI is approximately 3.141592653589793.
The value of PI is approximately 3.141592653589793.
The value of PI is approximately 3.142.
Jack    ==>    4098
Sjoerd   ==>    4127
Dcab    ==>    7678
Jack: 4098; Sjoerd: 4127; Dcab: 8637678
>>> 

希望本文所述对大家Python程序设计有所帮助。