python 基础9-拼接

参考文档：

https://zhuanlan.zhihu.com/p/90439125

1、百分号-字符串拼接：

　　1. %s 用法

　　　　print("I am %s my hobby is %s" %("lzf","play"))
　　 ==
　　　　print("I am {},my hobby is {}".format("lzf","play"))

　　2.  %s 可以传任意值　　　　

　　　　print("I am %s my hobby is %s" %("lzf","[1.2]"))

　　3. %d 只能传数字
　　　　print("I age %d" %(18))

       4. %f 打印浮点数，默认保留 6位小数
　　　　print("percent %f" % 99.123456789)

　　5. 保留指定位数，如 %.2f"
　　　　print("percent %.2f" % 99.123456789)

2、sep = " " 拼接

　　print("root","pwd","root",sep=" :")

3、format-字符串格式化

　　1. 传值为 字典
　　　　tp1 = "I am {name},age{age},hobby{hobby}".format(**{"name":"alex","age":18,"hobby":"play"})
　　　　print(tp1)

　　2. 传值为固定类型 :s-字符串，:d--int类型，:f--浮点类型
　　　　tp1 = "I am {:s},age{:d},mokey{:.2f}".format("alex",18,88.123456)
　　　　print(tp1)

 4、案例：

def test_1():
    a = '1'
    b = '2'
    print("Hello, %s %s. " % ("first_name", "last_name"))
    print ("Hello, %s %s. " % (a,b))

    print ("Hello,{}. You are {}.".format ("Alex", "18"))
    print ("Hello,{}. You are {}.".format (a,b))

    print (f"Hello,{a}. You are {b}.")
    print (f"Hello,{a}. You are {b}.")

def test_2():
    comedian = {'name': 'Eric Idle', 'age': 74}

    print ("The comedian is {name}, aged {age}.".format(name=comedian["name"],age=comedian["age"]))
    print ("The comedian is {name}, aged {age}.".format (**comedian))

    print(f"The comedian is {comedian['name']}, aged {comedian['age']}.")

# 备注：% 不支持字段类型，.format与f 都支持字典， f运行最快