【Python】str.format
format给人的感觉比%更有优势。
1：format的内容替换大括号
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>>> "The sum of 1 + 2 is {0}".format(1+2) 'The sum of 1 + 2 is 3' >>> ## 大括号中的0可以省略，采用顺序 >>> "The sum of 1 + 2 is {}".format(1+2) 'The sum of 1 + 2 is 3' >>> |
2：多个参数的例子
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>>> str = "My name is {0},I'm {1} years old.".format("xxf",20) >>> print (str) My name is xxf,I'm 20 years old. >>> ## 大括号中的编号可以去掉，采用默认顺序 >>> str = "My name is {},I'm {} years old.".format("xxf",20) >>> print (str) My name is xxf,I'm 20 years old. >>> ## 当然只要format的顺序与编号顺序相同即可。 >>> str = "My name is {1},I'm {0} years old.".format(20,"xxf") >>> print (str) My name is xxf,I'm 20 years old. >>> |
3：大括号的编号可以出现多次，只要能匹配上参数即可
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>>> "This {0} our class{1},It {0} a nice big {1}".format("is","room") 'This is our classroom,It is a nice big room' >>> |
4：通过标签对应参数
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>>> "My name is {name},I'm {age} years old.".format(age=20,name="xxf") "My name is xxf,I'm 20 years old." >>> |
5：利用列表下标对应参数
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>>> lt=["xxf",20] >>> "My name is {0[0]},I'm {0[1]} years old.".format(lt) "My name is xxf,I'm 20 years old." >>> |
6：格式限定：对齐、补齐
“格式限定符”，语法{:}
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## 将字符串a补充至10位，右对齐 >>> '{:>10}'.format('a') ' a' >>> ## 将字符串a，用b补充为10位，右对齐 >>> '{:b>10}'.format('a') 'bbbbbbbbba' >>> ## 将字符串a补充至10位，左对齐 >>> '{:<10}'.format('a') 'a ' >>> ## 将字符串a，用b补充为10位，左对齐 >>> '{:b<10}'.format('a') 'abbbbbbbbb' >>> ## 利用0补充至11位，字符串1居中 >>> '{:0^11}'.format('1') '00000100000' >>> |
7：浮点型，小数位
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>>> '{:.2f}'.format(3.1415926) '3.14' >>> |
8：千位符
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>>> '{:,}'.format(1234567890) '1,234,567,890' >>> |