Python-格式化字符串
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格式 描述
%% 百分号标记 #就是输出一个%
%c 字符及其ASCII码
%s 字符串
%d 有符号整数(十进制)
%u 无符号整数(十进制)
%o 无符号整数(八进制)
%x 无符号整数(十六进制)
%X 无符号整数(十六进制大写字符)
%e 浮点数字(科学计数法)
%E 浮点数字(科学计数法,用E代替e)
%f 浮点数字(用小数点符号)
%g 浮点数字(根据值的大小采用%e或%f)
%G 浮点数字(类似于%g)
%p 指针(用十六进制打印值的内存地址)
%n 存储输出字符的数量放进参数列表的下一个变量中
%s 格式化为字符串
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- >>> format = "Hello, %s. %s enough for ya?"
- >>> values = ('world', 'Hot')
- >>> print format % values
- Hello, world. Hot enough for ya?
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- >>> format = "Pi with three decimals: %.3f"//保留小数点后3个有效数字
- >>> from math import pi//导入pi的值
- >>> print format % pi
- Pi with three decimals: 3.142
关键字参数(substitute):
单词替换
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- >>> from string import Template
- >>> s = Template('$x, gloriout $x!')
- >>> s.substitute(x = 'slurm')
- 'slurm, gloriout slurm!'
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- >>> from string import Template
- >>> s = Template("It's $xtastic!")
- >>> s.substitute(x = 'slurm')
- "It's slurmtastic!"
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- >>> from string import Template
- >>> s = Template("Make $ selling $x!")
- >>> s.substitute(x = 'slurm')
- 'Make $ selling slurm!'
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- >>> from string import Template
- >>> s = Template('A $thing must never $action')
- >>> d =
- >>> d['thing'] = 'gentleman'
- >>> d['action'] = 'show his socks'
- >>> s.substitute(d)
- 'A gentleman must never show his socks'
用*作为字段宽度或精度
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- >>> '%.*s' % (5, 'Guido van Rossum')
- 'Guido'
转换标志:
-:左对齐
+:在转换值之前加上正负号
“ ”:正数之前保留空格
0:转换值若位数不够用0填充
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- >>> pi = 3.1415
- >>> '%010.2f' % pi
- '0000003.14'
- >>> '%-10.2f' % pi
- '3.14 '
- >>> '%10.2f' % pi
- ' 3.14'
- >>> '% 10.2f' % pi
- ' 3.14'
- >>> '%+10.2f' % pi
- ' +3.14'
字符串格式化范例
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- width = input('Please enter width: ')
- price_width = 10
- item_width = width - price_width
- header_format = '%-*s%*s'
- format = '%-*s%*.2f'
- print '=' * width
- print header_format % (item_width, 'Item', price_width, 'Price')
- print '-' * width
- print format % (item_width, 'Apples', price_width, 0.4)
- print format % (item_width, 'Pears', price_width, 0.5)
- print format % (item_width, 'Cantaloupes', price_width, 1.92)
- print format % (item_width, 'Dried Apricots (16 oz.)', price_width, 8)
- print format % (item_width, 'Prunes (4 lbs.)', price_width, 12)
结果显示:
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- Please enter width: 35
- ===================================
- Item Price
- -----------------------------------
- Apples 0.40
- Pears 0.50
- Cantaloupes 1.92
- Dried Apricots (16 oz.) 8.00
- Prunes (4 lbs.) 12.00
参考:
https://www.douban.com/note/269665597/
python全栈学习总结更新字符串:字符串格式化方法