python字符串string的内置方法实例详解

#__author: "Pizer Wang"
#__date: 2018/1/28
a = "Let's go"
print(a)
print("-------------------")
a = 'Let\'s go'
print(a)
print("-------------------")
print("hello" * 3)
print("helloworld"[2:])
print("-------------------")
print("ell" in "helloworld")
print("-------------------")
print("Pizer is a good student")
print("%s is a goog student" % "Pizer")
print("-------------------")
a = "1234"
b = "abcd"
c = "!@#$"
d = a + b + c
print(d)
d = "".join([a, b, c])
print(d)
d = ", ".join([a, b, c])
print(d)
d = "++".join([a, b, c])
print(d)
print("-------------------")
print("string的内置方法")
str = "helloworld"
print(str.count("l"))   #统计元个数
print(str.capitalize())   #首字母大写
print(str.center(25, "-"))  #居中
print(str.endswith("d"))
print(str.endswith("world"))
print(str.endswith("word"))  #是否以某个内容结尾
print(str.startswith("hello")) #是否以某个内容开始
str = "hello\tworld"
print(str.expandtabs(tabsize=10))
print("-------------------")
str = "helloworld {name} is {age}"
print(str.find("w"))   #查找到第一个元素并将索引值返回
print(str.format(name = "Pizer", age = 18))
print(str.format_map({"name":"Jone", "age":25}))
print("-------------------")
print(str.index("w"))
#print(str.index("www"))  #报错
print(str.find("wwww"))
print("-------------------")
str = "123abc"
print(str.isalnum())
str = "123"
print(str.isalnum())
str = "abc"
print(str.isalnum())
str = "!@$"
print(str.isalnum())
str = "中国万岁"
print(str.isalnum())
print("-------------------")
print("123456".isdecimal())
print("123456ff".isdecimal())
print("123456789".isdigit())
print("12345.6789".isdigit())
print("12345.6789".isnumeric())
print("-------------------")
print("34abc".isidentifier())
print("_34abc".isidentifier())
print("abc".islower())
print("abC".islower())
print("ABC".isupper())
print(" ".isspace())
print("-------------------")
print("Hello Jone".istitle())
print("Good morning".istitle())
print("-------------------")
print("Hello Jone".lower())
print("Good morning".upper())
print("Hello Jone".swapcase())
print("-------------------")
print("Hello world".ljust(20, "-"))
print("Hello world".rjust(20, "-"))
print(" Hello world \t \n")
print(" Hello world ".strip())
print(" Hello world ".lstrip())
print(" Hello world ".rstrip())
print("-------------------")
print("Hello Jone Jone".replace("Jone", "Pizer"))
print("Hello Jone Jone".replace("Jone", "Pizer", 1))
print("My title".find("t"))
print("My title".rfind("t"))
print("-------------------")
print("Hello world".split(" "))
print("Hello world".split("l", 1))
print("Hello world".rsplit("l", 1))
print("hello jone".title())
print("-------------------")
#重要的字符串方法
# print(st.count('l'))
# print(st.center(50,'#')) # 居中
# print(st.startswith('he')) # 判断是否以某个内容开头
# print(st.find('t'))
# print(st.format(name='alex',age=37)) # 格式化输出的另一种方式 待定：?:{}
# print('My tLtle'.lower())
# print('My tLtle'.upper())
# print('\tMy tLtle\n'.strip())
# print('My title title'.replace('itle','lesson',1))
# print('My title title'.split('i',1))