标签：ps1 line sig 比较 3.4 src sys type orm
Python的字符串格式化有两种方式: 百分号方式、format方式
百分号的方式相对来说比较老，而format方式则是比较先进的方式，企图替换古老的方式，目前两者并存。[PEP-3101]
This PEP proposes a new system for built-in string formatting operations, intended as a replacement for the existing ‘%‘ string formatting operator.
1、百分号方式
注：Python中百分号格式化是不存在自动将整数转换成二进制表示的方式
常用格式化：
1 tpl = "i am %s" % "alex"
2
3 tpl = "i am %s age %d" % ("alex", 18)
4
5 tpl = "i am %(name)s age %(age)d" % {"name": "alex", "age": 18}
6
7 tpl = "percent %.2f" % 99.97623 #打印浮点数
8
9 tpl = "i am %(pp).2f" % {"pp": 123.425556, }
10
11 tpl = "i am %.2f %%" % {"pp": 123.425556, } #打开百分比
示例：
1、%s 可以字符串拼接
1 msg=‘i am %s my hobby is %s‘ % (‘lhf‘,‘alex‘) 2 print(msg)
执行结果：
1 i am lhf my hobby is alex
2、%s 可以按收任何类型（ 数字对应字符串）
1 msg=‘i am %s my hobby is %s‘ % (‘lhf‘,1) 2 print(msg)
执行结果：
1 i am lhf my hobby is 1
3、%s 可以字符串接收列表
1 msg=‘i am %s my hobby is %s‘ % (‘lhf‘,[1,2]) 2 print(msg)
执行结果：
1 i am lhf my hobby is [1, 2]
4、%s传字符串或任何值， %d只能接收数字
1 name=‘lhf‘ 2 age=19 3 msg=‘i am %s my hobby is %d‘ % (name,age) #age可以用%d or %s,但用%s程序可读性差 4 print(msg)
执行结果：
1 i am lhf my hobby is 19
5、%d 只能接收数字类型，不能接收列表
1 # %d 只能按收数字类型 2 msg=‘i am %s my hobby is %d‘ % (‘lhf‘,1) 3 print(msg)
执行结果：
1 i am lhf my hobby is 1
6、%d 不能接收列表类型,会报错
1 msg=‘i am %s my hobby is %d‘ % (‘lhf‘,[1,2]) 2 print(msg)
执行结果：
1 Traceback (most recent call last): 2 File "D:/python/day5/format_type.py", line 14, in <module> 3 msg=‘i am %s my hobby is %d‘ % (‘lhf‘,[1,2]) 4 TypeError: %d format: a number is required, not list
7、打印浮点数
1 tpl = "percent %.2f" % 99.976234444444444444 2 print(tpl)
执行结果：
1 percent 99.98
8、打印百分比
1 tpl = ‘percent %.2f %%‘ % 99.976234444444444444 2 print(tpl)
执行结果：
1 percent 99.98 %
9、左边打印空格
1 msg=‘i am %(name)+60s my hobby is alex‘ %{‘name‘:‘lhf‘}
2 print(msg)
执行结果：
1 i am lhf my hobby is alex
10、打印空格加颜色(黄色）
1 msg=‘i am \033[43;1m%(name)+60s\033[0m my hobby is alex‘ %{‘name‘:‘lhf‘}
2 print(msg)
执行结果：
1 i am lhf my hobby is alex
19、不用格式化的方式
1 print(‘root‘,‘x‘,‘0‘,‘0‘,sep=‘:‘) 2 print(‘root‘+‘:‘+‘x‘+‘:‘+‘0‘,‘0‘)
执行结果：
1 root:x:0:0 2 root:x:0 0
2、Format 方式
[[fill]align][sign][#][0][width][,][.precision][type]
常用格式化：
1 tpl = "i am {}, age {}, {}".format("seven", 18, ‘alex‘)
2
3 #必须一一对应，否则会报错
4 tpl = "i am {}, age {}, {}".format(*["seven", 18, ‘alex‘])
5
6
7 tpl = "i am {0}, age {1}, really {0}".format("seven", 18)
8
9
10 tpl = "i am {0}, age {1}, really {0}".format(*["seven", 18])
11
12
13 tpl = "i am {name}, age {age}, really {name}".format(name="seven", age=18)
14
15
16 tpl = "i am {name}, age {age}, really {name}".format(**{"name": "seven", "age": 18})
17 ** 代表传字典
18
19 tpl = "i am {0[0]}, age {0[1]}, really {0[2]}".format([1, 2, 3], [11, 22, 33])
20
21
22 tpl = "i am {:s}, age {:d}, money {:f}".format("seven", 18, 88888.1)
23 s 代表字符串 d 代表整数
24
25 tpl = "i am {:s}, age {:d}".format(*["seven", 18])
26 * 代表列表
27
28 tpl = "i am {name:s}, age {age:d}".format(name="seven", age=18)
29
30
31 tpl = "i am {name:s}, age {age:d}".format(**{"name": "seven", "age": 18})
32
33
34 tpl = "numbers: {:b},{:o},{:d},{:x},{:X}, {:%}".format(15, 15, 15, 15, 15, 15.87623, 2)
35 2进制 8进制 10进制 x与X: 16进制 %：百分比
36
37 tpl = "numbers: {:b},{:o},{:d},{:x},{:X}, {:%}".format(15, 15, 15, 15, 15, 15.87623, 2)
38
39
40 tpl = "numbers: {0:b},{0:o},{0:d},{0:x},{0:X}, {0:%}".format(15)
41
42
43 tpl = "numbers: {num:b},{num:o},{num:d},{num:x},{num:X}, {num:%}".format(num=15)
示例：
ps1:
1 tpl = "i am {0}, age {1}, really {2}".format("seven", ‘18‘,‘alex‘)
2 print(tpl)
执行结果：
1 i am seven, age 18, really alex
ps2:
1 tpl = "i am {2}, age {1}, really {0}".format("seven", ‘18‘,‘alex‘)
2 print(tpl)
执行结果：
1 i am alex, age 18, really seven
ps3: 传字典的方式
1 tpl = "i am {name}, age {age}, really {name}".format(name="seven", age=18)
2 print(tpl)
执行结果：
1 i am seven, age 18, really seven
ps4: ** 传字典的方式 (跟ps3的方式是一样的）
1 tpl = "i am {name}, age {age}, really {name}".format(**{"name": "seven", "age": 18})
2 print(tpl)
执行结果：
1 i am seven, age 18, really seven
ps5: * 代表：列表
1 tpl = "i am {:s}, age {:d}".format(*["seven", 18])
2 print(tpl)
执行结果：
1 i am seven, age 18
ps6:
1 tpl = "i am {:s}, age {:d}".format("seven", 18) #["seven", 18]
2 print(tpl)
执行结果：
1 i am seven, age 18
ps7:
1 l=["seven", 18]
2 tpl = "i am {:s}, age {:d}".format(‘seven‘,18)
3 print(tpl)
执行结果：
1 i am seven, age 18
ps8: 2进制 8进制 10进制 x与X: 16进制 %：百分比
1 tpl = "numbers: {:b},{:o},{:d},{:x},{:X}, {:%},{}".format(15, 15, 15, 15, 15, 15.87623, 2)
2 print(tpl)
执行结果：
1 numbers: 1111,17,15,f,F, 1587.623000%,2
标签：ps1 line sig 比较 3.4 src sys type orm
原文地址：https://www.cnblogs.com/CK85/p/10292174.html
