python课堂整理8---字符串格式化

一、字符串格式化（% 和 format)

1. % s  主要接收字符串类型，也可以接收任意类型

tp1 = "i am %s my hobby is alex" % 'lhf'
print(tp1)

tp1 = "i am %s my hobby is %s" % ('lhf', 'dabai')
print(tp1)

、

tp1 = "i am %s my age is %d" % ('lhf', 11)
tp2 = "1 am %s my age is %s" % ('dabai', 12)
print(tp1, tp2, sep="
")

注意：%d 只接收数字，%s接收任意类型，但是最好物尽其用，便于维护！

2. 打印浮点数，默认保留6位小数，自动四舍五入。

tp1 = "percent %f"% 99.99675854
tp2 = "percent %.3f"% 99.99975854
print(tp1)
print(tp2)

3. 打印百分比

tp1 = "percent %.3f%%"% 99.99635854
print(tp1)

4. 传入值为字典

tp1 = "i am %(name)s age %(age)d" %{"name": "alex", "age": 18}
print(tp1)

tp1 = "i am %(pp).2f" % {"pp": 99.99}
print(tp1)

5. 可选项：+ 右对齐  -左对齐  后面的数字表示宽度， 下面的42控制的颜色

msg = "i am %(name) + 30s my hobby is dabai" % {'name': 'liu'}
msg2 = "i am 33[42;1m%(name) + 30s33[0m my hobby is dabai" % {'name': 'liu'}
print(msg)
print(msg2)

二、format用法: 

1. 按顺序对应

tp1 = "i am {} age {} {}".format("alex", 18, "alex")
print(tp1)

2. 根据后面索引对应

tp1 = "i am {2} age {1} {0}".format("alex", 18, "dabai")
print(tp1)

3. 传入值为字典时，注意前面加两个**

tp1 = "i am {name} age {age} really {name}".format(name = "alex", age = 18)
tp2 = "i am {name} age {age} really {name}".format(**{"name": "alex", "age": 18})
print(tp1)
print(tp2)

4.索引列表对应

tp2 = "i am {0[0]} age {0[1]} really {0[2]}".format(["dabai","22","aaa"],[1,2,3])
print(tp2)

5. 根据类型按顺序输入对应值

tp2 = "i am {:s} age {:d} really {:.2f}".format("dabai", 18, 99.9)
print(tp2)

6. 这种类型下，如果传入值为列表，前面要加 * 号

tp2 = "i am {:s} age {:d} really {:.2f}".format(*["dabai", 18, 99.9])
print(tp2)

7. 不同进制演示（x:小写16进制， X：大写16进制, o: 8 进制，b : 2进制）

tp1 = "number: {:b} {:o} {:d},{:x}, {:X}, {:.2%}".format(15, 15, 15, 15,15,15.2341234)
print(tp1)

tp1 = "number: {0:b} {0:o} {0:d},{0:x}, {0:X}, {0:.2%}".format(15)
print(tp1)

tp1 = "number: {num:b} {num:o} {num:d},{num:x}, {num:X}, {num:.2%}".format(num = 15)
print(tp1)