Python字符串三种格式化输出

name='xiaoming'
age=12
print("My name is %s,My age is %d" %(name,age))
#输出：My name is xiaoming,My age is 12

print("...{索引}, ... , {索引}, ...".format(值1, 值2))
#索引{}为空，默认按照顺序取值
print("...{key1}, ... , {key2}, ...".format(key1=value,key2=value))

name='xiaoming'
age=12
print('My name is {}, My age is {}'.format(name,age))
print('My name is {0}, My age is {1}'.format(name,age))
print('My name is {name}, My age is {age}'.format(name='xiaoming',age=12))
#输出：My name is xiaoming,My age is 12

# 先取到值,然后在冒号后设定填充格式：{索引:[填充字符][对齐方式][宽度]}
# *<20：左对齐，总共20个字符，不够的用*号填充
print('{0:*<20}'.format('hellopython'))
# *>20：右对齐，总共20个字符，不够的用*号填充
print('{0:*>20}'.format('hellopython'))
# *^20：居中显示，总共20个字符，不够的用*号填充
print('{0:*^20}'.format('hellopython'))
输出：
hellopython*********
*********hellopython
****hellopython*****

#保留2位有效数字
print("{:.2f}".format(3.1415926))
#转成二进制
print('{0:b}'.format(16))
#转成八进制
print('{0:o}'.format(10))
#转成十六进制
print('{0:x}'.format(15)) 
输出
3.14
10000
12
f

name='xiaoming'
age=12
#{}中直接使用变量
print(f'My name is {name},My age is {age}')
#{}中运行表达式
print(f'{1+2+3}')
#调用Python内置函数
print(f'{name.upper()}')
#用lambda匿名函数：可以做复杂的数值计算
fun = lambda x : x+1
print(f'{fun(age)}')
#输出
My name is xiaoming,My age is 12
6
XIAOMING
13