Python中字符串的学习

Posted 2021-03-08 xiaoleebaba

Python中字符串的学习

一、字符串的格式化输出

1. % 占位符
   • %s 字符串
   • %d integer
   • %x 十六进制 integer
   • %f float
2. 指定长度
   • %5d 右对齐，不足左边补空格
   • %-5d - 代表左对齐，不足右边默认补空格
   • %05d 右对齐，不足左边补0
     -浮点数：
     • %f 默认是输出6位有效数据， 会进行四舍五入
     • %.2f 指定小数点位数的输出 保留小数点后2位
     • \'%4.8f\' 4代表整个浮点数的长度，包括小数，只有当
       字符串的长度大于4位才起作用.不足4位空格补足，可以用%04.8使用0补足空格

二、字符串的format方法

• 顺序填坑：{} 占位符
• 下标填坑
• 变量填坑
• 对齐
  • {:5} 指定输出长度=5
  • 字符串 {:5}--左对齐
  • 数值 {:5}--右对齐
  • 使用 > < 可以避免字符串/数值对齐方法不一致
    • > 右对齐
    • < 左对齐
    • 中间对齐 ^
    • 不足的长度用*表示

三、格式化 f\'\'

• python3.6 后的版本支持。
• f\'名字是：{name}，年龄是：{age}\'

四、测试代码：

name = \'xiaolee\'
age = 45
height = 1.7234782342

intro1 = \'My name is %s, I\\\'m %d years old, and my height is %f Metres.\'
intro2 = \'My name is %s, I\\\'m %10d years old, and my height is %.2f Metres.\'
intro3 = \'My name is %s, I\\\'m %-10d years old, and my height is %4.2f Metres.\'
intro4 = \'My name is %s, I\\\'m %010d years old, and my height is %08.2f Metres.\'
intro5 = \'My name is %s, I\\\'m %x years old, and my height is %08.2f Metres.\'
intro6 = \'My name is {}, I\\\'m {} years old, and my height is {} Metres.\'
intro7 = \'My name is {2}, I\\\'m {1} years old, and my {0} is %08.2f Metres.\'
intro8 = \'My name is {name0}, I\\\'m {age0} years old, and my height is {height0} Metres.\'
intro9 = \'My name is {0:*<15}, I\\\'m {1:*>11} years old, and my height is {2:*^20} Metres.\'
introA = \'My name is {0:<15}, I\\\'m {1:>11} years old, and my height is {2:^20} Metres.\'
introB = \'My name is {0:#<15}, I\\\'m {1:$>11} years old, and my height is {2:8^20} Metres.\'
introC = f\'My name is {name}, I\\\'m {age} years old, and my height is {height} Metres.\'

print(intro1 % (name, age, height))
print(intro2 % (name, age, height))
print(intro3 % (name, age, height))
print(intro4 % (name, age, height))
print(intro5 % (name, age, height))

print(intro6.format(name, age, height))
print(intro7.format(height, age, name))
print(intro8.format(age0=age, name0=name, height0=height))

print(intro9.format(name, age, height))
print(introA.format(name, age, height))
print(introB.format(name, age, height))

print(introC)

程序执行结果：

本文主要参照这篇博文，测试程序重新写。
Python 字符串格式化输出的3种方式