test =  'asdasdwqd'
v = test.capitalize()#首字母大写
print(v)
结果：Asdasdwqd

test =  'ASDDWASD WasdafqwASD'
v = test.casefold() #所有字母都变成小写,casefold,对 Unicode 的时候用 casefold
print(v)
v1 = test.lower() #所有字母都变成小写,lower() 只对 ASCII 也就是 'A-Z'有效
print(v1)
v2 = test.upper() #所有字母都变成小写
print(v2)
v3 = test.swapcase() #所有大写换成小写，小写换成大写
print(v3)
v4 = test.title() #首字母大写
print(v4)
结果：asddwasd wasdafqwasdasddwasd wasdafqwasdASDDWASD WASDAFQWASDasddwasd wASDAFQWasdAsddwasd Wasdafqwasd

test =  'wASD'
v = test.center(20,'*') #共打印20个字符 不够的用*号从两边向中心补全
print(v)
test = "qiqiqiq"
v = test.ljust(20,"*") #共打印20个字符 不够从右用*号补全
print(v)
v2 = test.rjust(20,"*")#共打印20个字符 不够从左用*号补全
print(v2）
结果：
********wASD********
qiqiqiq*************
*************qiqiqiq

test =  'wsdadwdadasdasdasdasdASD'
v = test.count('a',3,10) #统计字符串里某个字符出现的次数。可选参数为在字符串搜索的开始与结束位置
print(v)
结果：3

test = "alex"
v = test.endswith('ex') # 以什么什么结尾
print(v)
v = test.startswith('ex') # 以什么什么开始
print(v)
结果：TrueFalse

test = "ale\tx\nale\tx\nale\tx\n"
v = test.expandtabs(20)#字符串中有\t 那么打印时就会把\t转换成20空格
print(v)
结果：ale                 xale                 xale                 x

test = "my name is "
v = test.find('m') # 从下标0开始，查找在字符串里第一个出现的子串，返回结果：0
print(v)
v = test.find('m',1) # 从下标1开始，查找在字符串里第一个出现的子串：返回结果5
print(v)
v = test.find('z') # 查找不到返回-1
print(v)
v1 = test.rfind('m') #从右边开始查找，返回结果：5
print(v1)
v1 = test.rfind('m',5) #从右边第五个下标开始查找，返回结果：5
print(v1)
结果：05-155

test = "my name is {name} , is ago {year}"
print(test)
v = test.format(name='qitian',year=23)#格式化，将一个字符串中的占位符替换为指定的值
print(v)test = 'i am {0}, age {1}'
print(test)
v= test.format('qitian',19)#格式化，将一个字符串中的占位符替换为指定的值
print(v)test = "my name is {name} , is ago {year}"
print(test)
v = test.format_map( {'name': 'qitian', 'year': '23'} ) # 格式化，传入的值
print(v)
结果：
my name is {name} , is ago {year}
my name is qitian , is ago 23
i am {0}, age {1}
i am qitian, age 19
my name is {name} , is ago {year}
my name is qitian , is ago 23

test = 'asdasdasdasdwq'
v = test.index('d',1,4) #查找下标 若不存在，找不到，报错，可以定义起始位置和结束位置 从下表1 开始查找d这个字幕，结束位置下表4
print(v)
v = test.rindex('d',1,6) #返回子字符串 d 在字符串test中最后出现的位置
print(v)
结果：25

test = 'aaaasdasdasdasdwqaaa'
print(test)
v = list(test) #转换成列表
print(v)
v2 = "".join(test) #转换成字符串
print(type(v2)) #查看类型
print(v2)
v3 = v2.strip("a") #去除两段字符a 默认是空格
print(v3)
v4 = v2.rstrip("a") #去掉右边
print(v4)
v5 = v2.lstrip("a") #去掉左边
print(v5)
结果：
aaaasdasdasdasdwqaaa
['a', 'a', 'a', 'a', 's', 'd', 'a', 's', 'd', 'a', 's', 'd', 'a', 's', 'd', 'w', 'q', 'a', 'a', 'a']
<class 'str'>
aaaasdasdasdasdwqaaa
sdasdasdasdwq
aaaasdasdasdasdwq
sdasdasdasdwqaaa

v = str.maketrans("abcdefj","1234567") #生成一个转换表, 要一一对应.
test = "bceja"
print(test.translate(v)) #用创建的映射表,test转换字符串
结果：23571

test = "1a2a3a4a5a6a7a8a9a"
v = test.partition("6a")  # 指定的分隔符。6a
print(v) #返回一个3元的元组，第一个为分隔符左边的子串，第二个为分隔符本身，第三个为分隔符右边的子串。
print(v[1])v1 = test.rpartition("8a")
print(v1)
print(v1[1])
结果：('1a2a3a4a5a', '6a', '7a8a9a')6a('1a2a3a4a5a6a7a', '8a', '9a')8a

test = "abcdefgabcdefg"
v = test.replace('abcd','1234',2) #替换，将abcd替换成12234，参数2，是替换的量 这里面说就替换二个
print(v)
结果：
1234efg1234efg

test = "asdawdqdasdqwxsxqwd"
v = test.split("d")
print(v)
test = "asdawdqdasdqwxsxqwd"
v = test.rsplit("w",1)
print(v)
#方法通过指定分隔符对字符串进行分割并返回一个列表，默认分隔符为所有空字符，包括空格、换行(\n)、制表符(\t)等。类似于 split() 方法，只不过是从字符串最后面开始分割。
sep -- 可选参数，指定的分隔符，默认为所有的空字符，包括空格、换行(\n)、制表符(\t)等。
count -- 可选参数，分割次数，默认为分隔符在字符串中出现的总次数。
结果：['as', 'aw', 'q', 'as', 'qwxsxqw', '']['asdawdqdasdqwxsxq', 'd']

test = 'ab c\n\nde fg\rkl\r\n'
print(test.splitlines())
test1 = 'ab c\n\nde fg\rkl\r\n'
print(test1.splitlines(True))
#在输出结果里是否去掉换行符('\r', '\r\n', \n')，默认为 False，不包含换行符，如果为 True，则保留换行符
结果：['ab c', '', 'de fg', 'kl']['ab c\n', '\n', 'de fg\r', 'kl\r\n']

test = "12aasd3"
v = test.isalnum()
print(v)
test1 = "12aasd3@$%#"
v1 = test1.isalnum()
print(v1)
结果：TrueFalse

test = "asaasd"
v = test.isalpha()
print(v)
test1 = "12aasd3@$%#"
v1 = test1.isalpha()
print(v1)
结果：TrueFalse

test = "123123123"
v = test.isdigit()
print(v)
test1 = "12312qweqw"
v1 = test1.isdigit()
print(v1)
结果：True    False

print("name".isidentifier())
print("1True".isidentifier())
结果：TrueFalse

test = "asdasda"
v = test.islower()
print(v)
test1 = "ddwqdDSD"
v1 = test1.islower()
print(v1)
结果：TrueFalse

test = "asjdhgjasd"
test1 = "12123123"
v = test.isnumeric()
print(v)
v1 = test1.isnumeric()
print(v1)
结果：FalseTrue

print("My Name Is".isprintable())

test = "123123"
v = test.isspace()
print(v)
test1 = " "
v1 = test1.isspace()
print(v1)
结果：FalseTrue

test = "Asdasd Asdas"
v = test.istitle()
print(v)
test1 = "Asdasd aAasdasd"
v1 = test1.istitle()
print(v1)
结果：TrueFalse

test = "asdasdasd"
v = test.isupper()
print(v)
test1 = "SADSADSA"
v1 = test1.isupper()
print(v1)
结果：FalseTrue

test = ['a','b','c','d','e','f','g']
v = test.append("z") #在列表末尾添加新的对象
print(test)
结果：['a', 'b', 'c', 'd', 'e', 'f', 'g', 'z']

test = ['a','b','c','d','e','f','g']
v = test.clear()
print(test)
结果：[]

test = ['a','b','c','d','e','f','g']
v = test.copy()
print(test)
print(v)
结果:['a', 'b', 'c', 'd', 'e', 'f', 'g']['a', 'b', 'c', 'd', 'e', 'f', 'g']

test = ['a','b','c','d','e','f','g']
v = test.index("c")
print(v)
结果：2

test = ['a','b','c','d','e','f','g']
v = test.insert(5,'z') #第一个参数待变在那个下表插入，第二参数是插入的值
print(test)
结果：['a', 'b', 'c', 'd', 'e', 'z', 'f', 'g'] 

test = ['a','b','c','d','e','f','g']
v = test.pop()
v2 = test.pop()
print(v)
print(v2)
print(test)

test = ['a','b','c','d','e','f','g']
v = test.remove("c",)
print(test)
结果：['a', 'b', 'd', 'e', 'f', 'g']

test = ['a','b','c','d','e','f','g']
print(test)
v = test.reverse()
print(test)
结果：['a', 'b', 'c', 'd', 'e', 'f', 'g']['g', 'f', 'e', 'd', 'c', 'b', 'a']

test = ['a','b','f','c','e','d','g','1','7','3','6','2','4']
print(test)
v = test.sort()
print(test)
结果：['a', 'b', 'f', 'c', 'e', 'd', 'g', '1', '7', '3', '6', '2', '4']['1', '2', '3', '4', '6', '7', 'a', 'b', 'c', 'd', 'e', 'f', 'g']

test = ('a','b','f','a','a','d','g','1','7','a','6','2','4')
print(test)
v = test.count('a')
print(v)
结果：('a', 'b', 'f', 'a', 'a', 'd', 'g', '1', '7', 'a', '6', '2', '4')    4

test = ('a','b','f','a','a','d','g','1','7','a','6','2','4')
print(test)
v = test.index('a',2,10) #2是起始位置，10是终点位置 进行查找
print(v)
结果：3

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
#根据序列创建key，并制定统一的值。
v = dict.fromkeys(["k10",123,"9999"],123)
print(v)
结果：{'9999': 123, 123: 123, 'k10': 123}

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
v = dic.get('ke1',1111) #指定返回值 1111
print(v)
v = dic.get('ke1') #默认返回值
print(v)
结果：1111None

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
for i,o in dic.items():print(i,o)
结果：k2 2k4 4k1 1k3 3

dic = {"k1": 1,"k2": 1,"k3": 1,"k4": 1,
}
for i in dic.keys(): #取出所有的keyprint(i)
结果：k1k2k4k3

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
#删除并获取值
v = dic.pop('k1',90)  #当key不存在时，返回第二值90
print(dic,v) 　　　　　#打印删除values
结果：{'k4': 4, 'k3': 3, 'k2': 2} 1

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
a,c = dic.popitem() #随机删除一个值
print(dic,a,c) #打印随机删除key,values.
结果：{'k3': 3, 'k2': 2} k4 4

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
v = dic.setdefault('k1','123') #如果值存在，获取当前values,
print(dic,v)
v = dic.setdefault('k1121','123') # 如果值不存在，添加设置的值，key：values,
print(dic,v)
结果：{'k1': 1, 'k2': 2, 'k4': 4, 'k3': 3} 1{'k1121': '123', 'k1': 1, 'k2': 2, 'k4': 4, 'k3': 3} 123

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
#更新 update
dic.update({'k1':123,'k123':'dasdasd'})
print(dic)
#另一种写法
dic.update(k1=3123,k5="qweqweasd")
print(dic)
结果：{'k123': 'dasdasd', 'k1': 123, 'k4': 4, 'k2': 2, 'k3': 3}{'k123': 'dasdasd', 'k1': 3123, 'k4': 4, 'k2': 2, 'k3': 3, 'k5': 'qweqweasd'}有值就替换掉，没有key，values，就添加上

dic = {"k1": 1,"k2": 2,"k3": 3,"k4": 4,
}
for i in dic.values(): # 取出所有的valuesprint(i)
结果：4123