Python用户交互&格式化输出

目录:

1. 用户交互
2. 格式化输出

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1、用户交互:

 input: 用户输入任何值,都被转换成字符串

>>> age = input("请输入年龄:")
请输入年龄:18
>>> type(age)
<class 'str'>

2、格式化输出:

 字符串格式化:

# %s 字符串点位符:可以接收字符串,也可以是数字
>>> name = 'Allen'
>>> print('my name is %s' % name)
my name is Allen

>>> age = 18
>>> print('age: %s' % age) 
age: 18

 整数格式化:

# %d 数字点位符: 只接收数字
>>> age = 18
>>> print('age: %d' % age)
age: 18
>>> salary = 666.66
>>> print('salary: %d' % salary)
salary: 666

 浮点型格式化:

# %f 浮点型点位符: 只接收数字
# %f 指定保留小数位数自动四舍五入,如下: 666.66 经过 %.1f 格式化输出后成为: 666.67
>>> salary = 666.66
>>> print('salary: %.1f' % salary)
salary: 666.7
>>> salary = 666
>>> print('salary: %.1f' % salary)
salary: 666.0

指定点位符宽度:

# %8s: 指定点位8个字符,右对齐; %-8s: 指定点位8个字符,左对齐
>>> print('Name: %8s Age: %8s' % ('Allen', 18))
Name:    Allen Age:       18
>>> print('Name: %-8s Age: %-8s' % ('Allen', 18))
Name: Allen    Age: 18